Amp B4 build help - stuck and shearer bottle bolt.

[markoc]

Sacrifice the rivnut and very carefully cut a line into it with a hacksaw, it’ll ruin the rivnut but could give you enough depth on the bolt to get a screwdriver on it. Plenty of plusgas too.

Figuring you've already thought of this though, and the bolt is stuck fast hence the shearing...

 

[Suprachrgd82]

If it's aluminum and you're willing to buy/borrow a right-angle drill or right-angle Dremel followed by a bolt extractor becomes an option. If the bolt is steel, you can have a welder place a nut over the stud and fill the nut to bond it and back it out. Either way, give it a dose of penetrating oil following the drill or weld (not before). Lastly, you can grind the rivnut and let it fall into the frame, silicone glue it inside to prevent it from rattling around.