[WDShaffer]

I will admit, I already have the welder...and I use a fiber cutoff wheel. The square stove bolt nuts fit right in place, too.

I have used heat before, too. Using a large torch tip or a rosebud tip, heat the offender to dull red (bright red too close to melting). If a nub is sticking out the back try to screw the remnant through. (Not a task for your PFs...very hot work).