How to extract broken bolt?

Heat and PB blaster or Liquid Wrench+ small vice grips from behind.
You'll get it out.

 

Just gonna leave this little nugget here

 

Shhhhh don’t tell anyone. Although sadly I didn’t use it for crack as the stereotypical engineering student at my college would have.

 

damn that explains a lot about why lifting my truck was so annoying. All the bolts were rusted from the beach and mudding. Kinda want to get kroil but if acetone and Transmission fluid work better what’s the point lol

 

This. Don't over complicate it with reverse drill bits or screw extractors. I've seen more damage done to hardware from inexperienced do it your selfers then I can count.

 

So, when you get the broken bolt out, what do you replace it with? Can you just get a matching bolt from the hardware store, or is this a special order item? Are there specific requirements for these bolts with specified torque specs, etc.?