Fitting the skins is a little tricky. You have to get the prepunched holes on both sides to line up with center lines that I drew on the spars and ribs. Here you can see the black lines on the forward spar. I spent a lot of time walking back and forth between the two sides of the wing. When you get everything lined up on one side, then it would be off on the other side. Since I didn't have a helper, it helped to use the orange cargo straps to snug it down.