This is my current situation. In way over my head

you have a bottle torch just melt it off then hit the hardware store for a new grade 8 bolt. just keep the torch on the nut and bolt. if that dont do it a chisel and a bf hammer

I guess cutting it flush (or clean), then driving it through with a drift or something would be the goal.

An angle grinder might be handy to remove any shoulder that's left.

You want your drift or whatever a little smaller than (it)....peening or bashing the end could peen it larger. If you got the head of the bolt out any on the back, you might cut it again under there, then coming OUT be careful not to peen any "mushroom " on the end.

I'm working with metal myself today. Safe to say I think my job is going a little better.

I bet you could get the end of a wonder bar between the suspension arm and the mount, just enough to make sure there is room for a sawzall blade.

VICTORY!!! Sawzall dremel tool and a flat head screwdriver. Took about 6 sawzall blades to finally get it and then the thread finally came free.

Trying to imagine the sound a swazall dremel makes. Maybe like a model airplane? "Step back, I'm firen up this bad boy". Glad you got it.