Technique to cut the vent holes on the cowl part 00009-L/R?

Anyone already done this and have a recommendation to get the job done well?

This is on page 37iS/U-17.

Thanks in advance too.

i haven't attempted anything yet.. but i've been thinking of using a dremel .. and finishing it off with sandpaper

I just started working on this myself. The issue I'm having is clearance between the material to be removed and the portions that are to remain. I started trying to drill from the bottom to the top (i.e. from inside the cowling to outside), but there's very little clearance in this direction once the bit passes through the fiberglass. I think it's probably better to drill from outside the cowling towards the inside.

I may pick up a flex shaft attachment for my dremel to see if that makes this process easier.