I'd also go for a skinny wheel on an angle grinder. You can cut most of the way through the welds and then knock them off with a hammer. Switch to a 36 grit disk and grind the welds down flat and you're ready for the grapple install. I've removed a bunch of stuff that way, and if you do get a little deep a quick line with the wirefeed before you grind the welds and you'd never know they were there.