Floor install

I didnt want to hijack 19 agains thread. I want to install an AMD complete center floor section. What I planned on doing was drilling the original spot welds, removing the floor and drop inthe new and spot weld again. Has anyboby done this? Is it practical. I realize the drilling would be time consuming but, thought it would produce the cleanest most original looking finished product.

Would a plasma cutter be usefull for cutting the spot welds.

Thanks