THINKWORK Bolt Extractor Kit, 13+1 Pieces Nut Extractor Socket Set, 3/8" Drive Rounded Bolt Remover, Lug Nut Removal Tool for Damaged, Rusted, Rounded-Off, Stripped Fasteners

I know this is the welding subreddit. You have so much access there! Try something like this: https://a.co/d/0j0XtzC6 Heat that bolt up. Get it nice and red. That’ll basically break it free all by itself. Hammer one of these bad boys on there and pull it out.