What is the Best Way to Break Loose an Over Torqued Bolt/Nut?

The dumb son of a f%^&#^& b*&^% of a previous owner, over torqued everything from the bolts that hold the fuel filter on to the rear diff refilling and draining ports. Even a breaker bar isn't moving them after they have been soaked with WD40. Here is a Toyota trophy truck with a 1UZ-FE based 302 stroker for your time: » 7/26/14 3:14pm 46 minutes ago