Laid out the holes for rib angle (7V6-3) & drilled. Lined angle with edge of skin, drilled & clecoed to spar. Positioned, drilled & clecoed splice end rib (7A1-1) in place. Marked the location of the hinge brackets (7A1-5) where they protrude through the lower skin. I then cut the slots by drilling several #30 holes & filing to size with a rat tail file. Updrilled all holes to final sizes.