Marked all spacer locations. Drilled holes for the center lightenholes. Drill #21 holes for the#5 rivets. Used 8/32 bolts and nuts to hold the pieces together after I drilled the holes. I drilled all the locations where ribs go first. I clamped using vice grip clamps on each side then drilled the hole using a number 30 bit then a number 21 bit. after drilling I would put the bolt and nut in the hole to hold it tight. Then I would do the opposite side. Moving top to bottom and side to side around the web splice. Drilled number 30 in the spar attach plate to hold the space in place. Drilled several of the number 30 holes on the spar web splice plate. so far so good.