quick question about floor pan removal. my pans are in 90 % great shape. the other 10 percent are the rear pans. if i want to cut out the bad sections to retain as much original sheet metal as possible. do i just cut the bad spots out.? or do i have to break the spot welds as well? also do i have to brace anything while cutting the floor pans so the body does not shift.

I do not have alot of body work experience. but i want to learn and i can weld and have a large metal back ground. just never did a floor pan before. so any info or experiences that you have had will more than help me out. thanks guys