Began upgrade on right wing. Drilled out rivets so extruded angle can be mounted. Cut existing light weight (0.032") angle. Milled about 1.5" of extruded angle thinner so it will overlap the end of the existing 0.032" angle to provide better transition between the thinner and thicker angles. Cut relief in the top front of rear ribs according to the instructions so the wider extruded angle will fit. Removed front 1/4" x 1 1/4" front spar cap. Trimmed extrused angle on both ends to fit.