Marked the placement of the right C-791 skirt brace on the canopy frame. Drilled 2 #40 holes at first and clecoed in the brace to check alignment of the C-660 skirt to lower edge of brace. Looked pretty god so continued drilling #40 holes. Checked alignment again and then drilled out to #30. Removed and deburred all holes in brace and frame. Repeated for left side. Marked canopy frame to line up C-660 skirts. Again started on right side and drilled #40 holes from front to back. Repeated for left side.