Prepared rear skins, filing and rounding edges and corners. Remove protective vinyl along rivet holes. Clecoed to skeleton and match drilled. Completed fitting ribs to leading edge skin. This proved to be more challenging than I anticipated. The fit is very tight at the leading edge. I followed the instructions and clecoed the top first starting at the front and working back. The fit was tight. Working the bottom was more difficult. I needed to apply a significant pressure to force the rib into the front part of the skin, frequently prying it downward using a small diameter punch or awl.