RE: CARF-Models 2013 Series 3.1m Extra 330SC
I glued the corners in with foam safe CA (they weren't drilled yet).
Give the CA a good 5 minutes to make sure it's cured. Set the hatch back on. I used the little hand drill and a 1/16" drill bit to drill for the hatch screws. Start in one corner and add the screw. Then go across 45 to the other corner and drill and add a second screw.
Drill each hole and put the screw in before you drill the next hole. In just a few minutes the hatch is perfectly attached. I used some #2 x 9/16 hex head servo screws from Micro Fasteners.