Man, that's going to be a LOT of work, no matter how you do it. WHY do
you want it removed? It could be an advantage having it there. For
instance, you could use it as a giant welding table. You could tack
weld pieces in place to hold them. You could weld machinery anchors to
it. You could weld jigs to it for large frame-ups or bending patterns.
A lot easier to do and change than drilled anchors in concrete. Think
about it. Bob