Removing welded-in subframe connectors

[carbuff]

I'm looking at possibly purchasing a car that has a 6-point cage and a set of welded-in SFC's. Whichever SFC's these are, they do not come through the floor but run along underneath it. I haven't seen this in person yet, so I'm having to rely on the seller to convey the information.

Assuming that this is true, how much trouble would it be to cut out the SFC at the rear where it ties into the rear frame without destroying that area? I don't care about the subframe itself, that would be replaced. But as long as the floor isn't cut and I could somehow cut out the SFC from the rear, I would be happy with that.

Also, a similar question on the cage. Again, I'm waiting for pictures of how exactly it's tied into the car, but if I don't like how it's currently made, I presume cutting that out wouldn't be too bad. Concern would be whatever plates are welded to the floor that the tubes attach to...

Thanx!