One thing that has worked for me is to soak a piece of cloth with penetrating oil, place the cloth on the bolt(s), and walk away for a day. You may have be a bit creative with the cloth, but the idea is to keep the bolts "wet" and give the oil time to work in as deep as possible. Then use the long breaker bar to snap the head off the bolt as you cuss like a sailor.
Good luck.
Good luck.
