Not a terribly difficult page. The spars pass through the side skins, so there must be a hole for them to do so. The factory cuts the same hole on both sides, but leaves it too small for either. The spars aren’t quite symmetrical either, since the spars pass in front / behind each other. All I had to do was (double & triple check before starting) cutting the appropriate openings.
Left Skin w/ Spar Cut-out
Right Skin with Spar Cutout