Flap rivets

Just finishing the left flap and I am stuck on the top LP-4 pop rivets that hold the spar to the ribs, the holes are right under the top skin curved flange, I have two pop riveters and neither will fit under the flange to pull the rivet. I do not want to bend the flange and potentialy cause a crease, what did you guys do??

2 things I did there...

1) Bend the Pop Rivit shaft at an angle right at the rivet shoulder, insert the rivet then the pop rivet gun at an angle.

2) I had to borrow a smaller pop rivet gun, with a narrower head.

Hope this Helps.

Kind Regards

Rudi