I put Christmas lights inside the pant so I could see where the holes were that I had drilled in the inboard bracket. I found them and drilled them.
Eventually I got the pant all drilled and positioned. And re-measure its alignment. I made several iterations of moving the holes to get better alignment both laterially and pitch. It was kind of a pain in the butt to get these right. Finally they are close. To make them more perfectly aligned is just a myth because I'm within 1/2 hole diameter of the right location; the fuselage centerline is close but not perfect; the measuring squares are only close; ever time I measure it looks different. This is a little like doing the canopy. I'm glad I'm not building an entire fiberglass airplane.
Fortunately fiberglass is easy to fill and redrill.