I used a dremel tool with the angled stone bit (looks sorta like an arrowhead with a rounded point). I drilled a hole large enough to accommodate the head of the bit, and just pushed it in slowly, until I got the desired size. I did the same thing with the cooling vents on the nose. Just take your time and let the wheel do the work. Get it close, then take some 400 wet/dry sandpaper and smooth out any edges. That also takes the stray fiberglass shards away cleanly.

I used a new drill bit for the holes for the screws.