Floor install

Brace the structure so it will not move. (door jams)
Air chisel the floor around the uni body structure.
Ues a 1/4" drill bit to just knock the head off the spot weld, run the air chisel up the uni-body.
If the air chisel starts to rip the uni-body, stop and use the 1/4" to knock the top of the head off.
Easy, time consuming, and requires craftmanship.
Keep your head clear and you can do it.