This part kind of sucks. There's really no way around it, it's just tedious.

Sand the turtle deck face to size, stop when you reach flush with the balsa sheeting.

install the top formers at F3,4 and 5. Watch your stringer slot heigth here, the bottom of the stringer should be 1 1/4" from the top of the fuse.

Lay the stringer into the slots and let it extend past the face of the turtle deck. Make sure everything is straight and level, then mark the turtle deck so about 1 1/4" of stringer extends into the turtle deck. using blades and files, cut into the side of the turtle deck. The stringer width apart is not so critical, and can vary a bit depending upon how your sheeting turned out (it can be a little narrow or a little wider, it doesn't matter). But cut the stringer slot into the facing so that the outer edge of the stringer is slightly under 1/8" inside of the outer skin/face at the turtle deck.

Gently and carefully sand the top former stringer slots so that you have a nice gradual curve in the stringer from F4 to the turtle deck. It should be a little rounded, but not sticking WAY out.

Glue in the stringers from the firewall back to the turtle deck, extending the stringers into the slots you cut in the turtle deck. Use Polyurethane glue at the turtle deck, CA everywhere else. You may have to make a relief cut into the stinger at F2 so it makes the sharp bend downward to the firewall.

Let this dry completely.

Now take a sanding block and carefully sand the stringers and fuse top former sides so that you have an angled flat surfrace to glue the sheeting to.

The sides of the top formers at the bottom shoule be just inside the outer surface of the fuselage side so you can later sand a nice curve into it.

Now glue reinforcement plates to the front side of the top of F2 (the curved piece). This is where the canopy pins will insert. I make mine out of 1/16" phenolic, but 1/8" AC ply will work too.

Now set the angle using the top stringer that runs from F2T to the top of the firewall. Glue on the top of F2 using thickened epoxy. You need to sand a slight angle on the rear of the top of F2 so you have something to glue to. Remember keep paper towels handy, and remove the excess glue.