i was trying to take off my cant and the damn bolt broke. Any suggestions on how to
a) get bolts off without breaking them
b) get the bolt that i broke out of there
c) replace the cat with a straight pipe.

 

a) Use a penetrating solvent such as WD-40, Kroil, or PB Blaster.

b) If a sizable stub is exposed you could use a solvent on the rusted threads and then grab the stub with a stud remover. If no stub is exposed you have little alternative to drilling it out. Use a hardened drill bit for this job, and use eye protection while drilling.

c) Don't do this. It's illegal.