Interior trim removal and fabrication

Hoping to get a little help and information.

I currently have a 96 XJ, carpet is garbage and the interior trim isn't faring much better. I would like to remove all the interior trim, except for the doors and cover the holes with sheet metal or abs sheeting. And using Raptor Liner to coat the interior.

Has anyone attempted this, if so, how critical would it be for me to have a metal brake to attempt this? My wife wants to reupholster the headliner as well, I believe the trim holds it in place.

Thanks in advance