For the big cut-outs I use a hole saw in the small drill press, or you can use a hand drill. This
will rough-out a nice big hole, and get you started.

Then use a drum sander to do all the rest of the opening for the engine.

Then use a small drum sander in the drill press, or the Dremel with a small drun sander
fot the detail work. If you keep the edges and corners of the cowl round, it will lessen the
chances of it cracking from vibration later.

Using the drill press works best because it holds the cutting part for you. You can use both
hands on the cowl, lessen the danger of flying parts, and have better control of the cutting process.

Use a mask, and do not breathe the fiberglass dust....not good.

FBD.