The leading edge has to be accurate as it will be the position guides after the glue is place on the airframe:
Apply a thin trace of Gorilla polyurethane glue, remembering that it will expand 2 o 3 times it's volume. This also helps with an excellent grip.
As soon as the glue is applied through out the part to skin, position the skin over the frame using the leading edge pin holes previously made. Next I put as many pins as I can to get a super tight L.E. adhesion.
Magazines and soft books are the best to help the skins stay conforming to the structure.
In 4 hrs. the top of the wing will be ready to prime.
JG