My brother and I are tackling his clutch in his 94 ranger 2wd. Everything was going smoothly until we reached the step to remove the mounting bolts. Most of them were coming out fairly easy. But the one on the top towards the passenger side will not budge. It's a 13mm bolt, I've got excellent leverage and it won't budge with all my strength. I've tried jacking it up to relieve pressure, I've been hitting it with pb blaster, I've tried to use breaker bars and nothing. Won't even move at all. It doesn't look rusted or anything. I'm just wondering if there is an easier way to tackle this?

 

Can't think of anything except heat and cool
Heat bolt then cool it quickly with compressed air if available, if not cold water