Used a vacuum to grab the chips and also used paper towels to keep chips out of engine, a paint marker works great for marking drill holes and timing marks. keeping the holes close to the inside edge of the gear you actually are not drilling much fiber because the fiber is cast onto a metal insert. so after drilling and tapping I don't think the structural integrity is affected.
https://youtu.be/vuFAypO4G4U
Try the YouTube link