On page twelve of the instructions, under the heading "assembling the fuselage", step three tells you to fit and glue the belly former. Then in step four it tells you to slip the wing blocks in place. These two steps must be worked together otherwise you can't install the blocks after the belly former dries. When you assemble the fuse sides you need to thoroughly wet the sides, tape and clamp everything together, as the sides have a slight curve to them and are fairly thick. A 50/50 solution of alcohol and water work well for this. I found that if you wet and clamp everything and let it dry and then wet it again while you glue everything it works the best. Don't try to bend it all at once. Also try not to work too big an area at a time. When you are done with these steps you may want to drink whatever is left of the solution. It can be tricky. The payoff is you end up with a nice fuselage and not a square box. Good luck.