Used an automatic center punch to mark the 9 holes on the larger piece of each HS 908 attach angle. DO NOT DRILL THE TWO HOLES ON THE SMALLER PIECE OF ATTACH ANGLE! I then used a 1/8th drill bit to drill out the 9 holes on my drill press. I clecoed the attach angles to the Horizontal Stabalizer front spar. I used a piece of L angle clamped to each attach angle to keep them aligned properly.