Here is quick start of my Build-Log of a shortnose F100D (modified single seater version) but instructions will work almost the same for the standard F100F (twin seater).
The single seater gets a shorter nose and so a larger big enough inlet, it provides very good thrust without the need for the original FlyFly cheaterhole (you can still do the cheaterhole for for more Jet sound, perhaps I will try later and report)
Because the twinseater long nose inlet is smaller you must use the original FlyFly cheaterhole behind the nosegear (this to get enough air for your Fan). 
F100D FastFoam Version with extra parts like balsa wood trailing edges / leadig edge extensions/ extra spars and many improved steering parts.
precision drilled ‘sloppy free’ stronger 4mm elevator bearing blocks, Carbon rudderhorns for elevators and ailerons. 0,1mm thin hinges and metal kwiklinks
Optional in my shop is the extra F100D single seater scale canopy (ParflyerPlastics set) Original 2 seater canopy is also still with the kit so you can decide later what version you will build (the longnose twinseater needs less modification and saves build time) . Also it is possible to put the Parkflyer single seater canopy on top of the longnose (designed to fit the original FlyFly nose and convert it into a single seater)
I start with the main wing and its important lift angle modification:
I will bring the wing back to the original moulding design. After my first tests the maingear proved to be 6cm to far backwards: it does not want to take-off!! so perhaps this improvised high lift angle of main wing was a sort of remedy for an early design error ?? I am going to move the mainwheels 6cm to the front and bring back the wing to original moulding position. This F100 must become a real FastFoam high performance Jet, and there is only one way to start: cut the wings off!!
so cut the wing off with a fresh cutterblade (cut from 2 sides and try to stay vertical with your blade) 
you start building a JePe FastFoam Jet by destroying the original kit! 
make sure the wing root end is flat (use a sanding block) 
use (Bison)expanding PU-Glue to glue the EPS (Styrofoam) parts back together 
use some Scotch Tape and needles to keep the 2 parts in position (wing profile must now match with the top surface of the centre block: very easy to find)
wingroot section must be flat on topside (flat angle of wingroot with the topside of the centre block). Follow the panel lines to find same spot to put a ruler or Balsa board on top of the surface
use Scotch tape+needles from both sides to keep it in right angle and position 
after hardening you must cut a sleeve for carbon strip-spar on topside (16,5cm from trailing edge) 
sleeve must be 15cm long (prepare both wing panels) CAUTION! by accident this position is just over the ‘moved’ mainwheels so you must put in the carbon FLAT and not vertical , otherwise you get in trouble with your wheels(we still have to move the landing gear 6cm to the front !) You also can wait with this carbon untill you made the wheel modification
cut a 2x piece of 15cm carbon and sand the surface for good glue bonding 
again use some PU-Glue to glue the carbon strip into place (no need for Epoxy glue: PU Glue is super for EPS and Carbon ) 
some Scotch tape to keep the expanding glue down in the sleeve (same for other wing) BUT the carbon should be Flat mounted just into the surface and not vertical (remember your wheels will be right under this carbon strip)
below you always must sand the contact surface first so the PU-Glue can make best possible bonding 
hold the 2 wing panels together with tape and needles 
Important! Tape the rear fuselage together and use it as a mould for correct fit of the wing 
Important! : pull the rearside of the wing tight to the fuselage. In the centre join you will see a 1,5mm hight difference between the 2 wingpanels but that is thickness difference error of moulding parts. Use the rear fuselage and ductape to get correct closed tight fit to fuselage
on the frontside the 2 wingpanels should match perfect inline
all parts except the canopy can be glued with the PU-Glue, even Nylon blocks and epoxy rudderhorns (on this EPS / Styrofoam Model) 
after hardening it is time to make the bottom spar (use a saw blade to make 2 cuts at 25 and 26cm from trailing edge) 
use a file and a Dremel tool to lower the carbon strip some 2 mm flat into the wing foam
cut carbon strip at 40cm and do not forget the sanding for good glue bonding 
there is the PU-Glue again.. 
use some needles to keep the strip down (foqam will start expanding) Also use remainders of foam to fill-up the sleeve in the centre block 
after hardening you need to cut away the expanded PU-Foam 
and finish the wounds with ‘Easy-Foam Filler’ 
these plywood parts come with the original kit so best put them in place. Later you must drill 2 pieces of 4mm carbon pins into these mounting lip (just below the plywood so deep as possible)
inside of the wing: you can see the carbon strip from bottom side of wing passing from left to right wing 
this whole cheaterhole bay can be closed with some 1,5mm balsa sheet (we do not need this extra hole because we have shorter nose and bigger air opening in the F-100D single seater) For the Longnose it is better to leave the cheater open.
some more plywood at rear end of wing 
Cut the balsawwod 5x15mm trailing edges to lenght and glue them with PU and keep them in place with Scotch and needles (I do not cut the ailerons free: first after glassing)
you will get a 15mm wider wing 
you can see the sanding area of Flaps here (between pannel lines and balsa trailing edge)
there are some flat balsa strips with my kits: use the for leading edge extension (make sharper nose to the wing profile) Picture before extension
picture after extension 
just glue the balsa strip on with PU and needles, after first raw sanding you can fill them up from behind with Easy Foam Filler (picture below is from hawker Hunter but idea is the same)
now because of balsa extension you can bring the frontpart of the wing profile into sharper shape (have a look at white sanded area untill the panel lines). Use a nice long wooden sanding block for this(full length of your sanding paper)
Use 10cm long suspension legs with nice large 70mm light foam Wheels (have them drilled for 4mm shaft) . You can trim-off 1 winding of the suspension spring so it is a little softer
Caution! after first testflight I had to move the maingear 6cm to the front. If you dont do this the too far rearward maingears will not bring your model into rotation and you will only race over your grassrunway instead of taking-off into the air!
a full 6 cm to the front makes the difference between a racing car and a Jet: if you do not move the gear you will NOT take-off. 6 to 6,5cm to the front works perfect!
You can do this much better !! (my experimental prototype below)
the mounting plates need some anchors: drill 4mm pins under an angle deep into the wing and glue them with PU-Glue or epoxy
ailerons ultra thin hinges(0,1mm!) can be Glued with slow Epoxy on top of the wing surface. Use at least 4 next to each other (do not change direction: have a look at the picture because they are only strong in 1 direction!). Finally you wing will be glassed with 25gr tissue and glassing will go over the ultra thin hinges.
Ailerons are relative small so you can use 2,2 kg 14gr servo’s (metal gear/metal shaft) like the Corona 929MG Digtal . change the standard servo pocket and turn the servo wheel inline with flight direction.
Epoxy rudderhorn is glued deep into the foam with PU-Glue and connection to servo made by Ball-Link (do not forget to secure the M2 nut with strong green Locktite!)
there is a long spar from glas or carbon that you can glue in bottomside of the wing (in some kits it is already installed but do cut it for a bomb or droptank gadget)
OK now we modify and shorten the F100D nose with 7,5cm (or 3 Inches)
remember: you can use both types of canopy on the standard long nose and use the cheaterhole (this will save you a lot of time!)enlarge the ducting in the neck (just before the wing)
foam on topside of wing mounting can be very thin because wing can never escape in positive Hi-G turns (and for negative-G this foam has no use)
I use a metalsaw blade as cutter . clean it up with some 150 grain sandpaper and EasyFoamFiller
on the right fuselage part you can see how the ducting ‘opens-up’ after removing this piece of foam
the nose of the F100D must be 7,5cm shorter (3 Inch). 
you can cut it with a hotwire or just a knife 
we want to leave about 8mm of total foam thickness for a nice sharp radius 
a fresh new raw halfround file is my best tool for this (and FAST!!) . Use some soft protection under the fuselage.
remove foam as deep into the neck of the fuselage as possible (here some 15 cm) 
about 8mm material left for radius (don’t worry for sharp intake lip at this long distance from the fanunit: air needs about 6x the intake diameter to calmdown back to laminair airflow)
now you get plenty of air so you don’t need a cheaterhole 
big super sucker! and below the old small sucker.. 
in the topside of fuselage there is a cooling hole that I closed . 
One other ESC-cooling hole just behind the Fan is also closed (just on the picture) 
Nose Gear
complete section (about 4 cm wide) is removed so a plywood mounting plate can be glued in place (all the way from one side to the other). Use a steel sawblade as cutter.
4cm wide sleeve is now complete cut
Plywood mounting plate is made from strong 5mm thick 8 layers thick, from one side to other side glued with PU-Glue and foam blocks are also back in place ( I will make a fitting plywood mounting plate for the F100 soon)
much of the cheaterhole can be closed and there is a corona 929MG Analog servo for steering
nosegear suspension leg is 100mm long and wheels are 45mm drilled for 4mm shaft 
Main Hatch
You have to cut out a large Hatch on top of the fuselage. Cut the sides along the panel lines under a 45 degree angle
follow the ‘grand canyon’ panel lines for the size and cuts of the hatch
2 packs of 4s 5400mAh should fit in easy and a big controller (9s or 10s must also fit) I have now even 6s+5s x 5400 inside! a 6s in front and the 5s in rear (all weight must be pushed backwards to move the CG to 27,5 cm)
Elevators
glue balsawood trailing edges to the elevators, also sand the leading edge nice thinner. Forget the hinges on the picture (it will be an all moving elevator panel)
I made stronger 4mm steering for you. Nylon bearing blocks are precise drilled . Use some sand paper to sand the glue surface of these nylon blocks and glue them with PU/Glue into the foam (like original construction). Be sure that no glue gets into the drilled holes (use a little peace of tape to close the inner hole before you push it into the fuselage). Once the stabilizers are working you can glass one extra 25 gramm glass tissue over the Nylon bearing block area. I know that some Models like the Mig-29 this construction can be to weak but on this mounting place in the F100 it is a very strong solution, important is to keep these large stabilizers sloppy free and the right parts come with my fastFoam kit (servo’s like the TGY-2216MG are also a must have to keep this system sloppy free!)
after the blocks are fixed into the fuselage you can testfit the elevators and glue the steelwire into the panels (check the angles from behind the model) 
when steel pins are glued into the stabilizers you can glue the carbon elevator steering to the elevator sides with some epoxy. Also be sure to use green or red strong loctite for the M2 ball-link nut (very important!)
cut the TGY-2216MG servo’s into the foam and glue them in place with PU-Glue. Note that the servo’s are turned outwards by 2? degree to meet the ball-links in line
use a dremel to cut the servo wire sleeves and finish them with EasyFoamFiller(do not pass the bearing blocks to close: go with servo cables direct to the frontside (I had no choice because of my prototype experiments)
TailFin
bring size of the F100F back to smaller F100D tailfin. 
some sanding work to do: make leading edge thinner and sharper, and a balsa trailing edge 
make it scale thinned detail here
time for sleep now..tomorrow the single seater canopy conversion
F100D single seat canopy
the JePe FastFoam F100D kit comes with the Parkflyerplastics canopy set (if you have this set already or want to stay with the standard double seater canopy it is possible to order the F100 without this cockpit option)
the canopy has to be moved backwards for our special shorter nose F100D version. look at the panellines for the foam cuts
the cockpit tub must be more narrow on rear section so you have to cut it 1x 
you can see some extra foam in the front of the canopy: the canopy is moved just 1 panel line backwards 
mark the front section sides and cut them more narrow so the cockpit tub starts to fit slowly
the first few cm have to be lowered also: you will notice that your cockpit tub will fit better and better…
use some scrap balsa and plywood to hold the front of the canopy down 
cut the rearside to lenght by looking at the panel lines
install the canopy lock and cut the piece of foam in front of it loose 
the canopy tub is now glued with fast Epoxy but only to this ‘loose piece of foam’ (that has the tube for the lock inside) . It does not have to look pretty because a large part of the canopy rear section will be painted/sprayed so you can not see anything here..
use some tape and fast epoxy to keep the rear section of the tub glued together (more narrow than the original) 
than you must become an artist first before you can move on (the instruments are cut from the standard decal sheet that comes with the Jet) 
than you must sand the contact surface of both the canopy and the cockpit tub and glue them together with some fast Epoxy (use some tape on you fuselage so they will not glue to your fuselage)
before you can glue you must cut the clear canopy step by step untill it fits (small steps , many times..)
For my next canopy I will keep the bottom canopy tub a few mm oversized so it makes a nice rounding and perfect join to the fuselage. this is more scale and much easier because glued can not get between the clear canopy and the fuselage and it is easy to use some filler to get this nice rounding . Also it will be more easy to make the clear canopy cut to size and hide the raw ending with some filler .The full scale one has this cockpit roundings! ps: look at this handsome testpilot : is it JePe himselve ??almost ready to go??
Some more cosmetic Finish to do:
EPS Foam quality of this kit is OK but moulded parts do not fit 100% on all places..You have to sand off some material from the Belly . Best tape rear part of fuselage for protection and use a block (start with some raw paper and finish it with easyFoamFiller)
I did not want to look between fuselage and wing join so I put some vinyl plastic in between and made some filler to make a small rounding 
I use EasyFoamFiller and mix it with some Epoxy to make it very strong (also a little of PU-glue will work but can make gas bubbles!). The fact that EasyFoam Filler is water based proved to be no problem for a mixture with epoxy(works absolute fine together)
After hardening you can do easy sanding with some 150 grain paper 
than I put a stripe of 25gram glass over the roundings . I always use PU-Finish because I am in a hurry to get this Jet airborn! 
after removing the wing you can remove the protection vinyl tape and sand the roundings back to very small (the full scale original has no roundings but this finish detail gives your ‘just a foamy toy model’ an ‘super expensive real cool deluxe expert/profi’ look!
Sorry I had no time to update this blog but will make time this week. For start I placed the maingears 6cm to the front (towards the CG) this to get better rotation. The original maingear position proved to be too far backwards and almost impossible to get this jet from grass runway. Now no problem ! see my video of yesterday: