Morning Mac,
I done this exact task in my old commuter a few years ago. I had a complete false floor kit to install but had the boot mounted CD Changer that I wanted to retain which came from a non false floor set up. Therefore I had to cut the holes out as per what you’re considering.
It wasn’t an easy task as the materials are quite thick and only had a Stanley FatMax available at the time, when trying to push the knife blade in I kept going past my template lines. It wasn’t the most tidiest off jobs but totally achievable. All of my shoddy cutting was covered by the plastic cover that the false floor sits on. Just very unsightly when the covers were removed for any reason.
I just made a template from the side panel with the holes.
Now I have a Dremel I’m very confident that I could produce a much better finish.
Give it a go as it’s easy enough to do, getting that factory finish look is where it’s difficult but given the right tools and taking your time will see you persevere.
Kind regards,
Tom