The driver and passenger side floor had some rust holes. The rest of the car has ZERO cancer. Floors are easy to replace so i went to work.
I lifted the car up so that I can see what was underneath the floor. I was worried I would hit some structural members. But, there really isn't much under the footwell.
When I was cutting the floor pan I was being extra careful. If the abrasive cutoff wheel slowed down or sounded like it was struggling I would back off a bit. The dense material would be the fram rails or support rails.
I tried to cut a sqaure out to make it easier to replace the panel. There wasn't that much rust but it is just easier for me to replace a square rather than a bunch of small sections.
The final pictures shows how I started to clean the weld area as well as fixing any un-straight cuts.