[Cook&Dunning]

I've done it. It's messy and time consuming but can be done. The biggest issue will be protecting your interior and glass from all of the sparks. You'll want to remove any interior bits that are in the line of fire, including the carpet. There will be a ton of metal dust so you'll want to wear a mask, cover up vent holes, etc. You could just remove the front of the cage but it will be hard to do without damaging the headliner, you would want to remove the quarterglass for better access and protection. Dirty job, not very fun, but do-able.

This is great advice. I pulled the roll cage from my 89 track car. I had gutted the interior, but grinding down the door sill mounts - look the same as you have - I managed to catch fire the sound insulation / padding. Scary couple of minutes - thankfully all ended well. Make sure you have a fire extinguisher nearby, and maybe a ready to go garden hose for worst case.

I also managed to trash the passenger window with flying sparks. Live and learn.