On my tele body last night, I wound up using a dremel to remove a little bit of the clear coat spray inside and very lightly ream around the top of the holes. Then I put a little wax on each ferrule, pushed them in as far as I could with my thumb (which wasn't far). Finally, making sure they were straight, I used a scrap of credit card plastic material over each ferrule and tapped them in the rest of the way with a hammer. All six took about 15 minutes; easiest part of my build so far.
