Before I broke the bolt

So I broke that bolt off in red and there looks like there's no way to replace it as it's inside the body. What's the best way to replace it? I'm a fabricator so I was thinking of cutting into the body, try to pull the old on out and tac weld a new 10.9 bolt in it's place and patch the hole. Is this doable?

 

is the bolt seized, or you just over-tightened it?

 

Welcome from Florida. If it is broken off flush with the body you can try and get a 90-degree drill in there to dill out the broken off piece.