Oh boy I hope I can explain this as good as I can model.
One thing to keep in mind is... this is ALOT easier then it looks/sounds. So don't make it harder. Make a few small cuts at a time and test fit 10 times!
Step 1.
Remove the blue shaded tab on the upper nose.
Mark a spot about 4.5mm from the rear edge of the upper nose on both sides. Cut a slight arc from the 4.5mm point back to the center of the rear edge of the upper nose half, then repeat the other side. The smoother the line, the less putty you use later. Test fit the upper nose to the upper body, file till everything is straight.
Then glue the upper nose to the upper body. I added some styrene and putty on the underside to re enforce the parts together. Remember you gotta do alot of sanding to remove the hump from Italeri. Add putty to the top for any gaps... and bring out the sand paper!
I spent hours sanding the back of this plane. This step needs to be made no matter what, even if you don't mod the Raptor you'll still need to sand this baby good. So don't turn away now!
I used 5 different grits... the first being M-100. The final being 2000. I think. I'll still do a bit more before I paint.
Now You'll also need to make the gun port longer, since this area got shorter with the cut. I went toward the tail since the prototype shows the door stopping right at the mark we made the cut. So in fact we are making the door correct!
Ok I think we are done with top. Easy right?
Step 2 soon.