Last fall, I had trouble with the rotors on my wife's Cherokee. I took a six-foot long iron stake my father uses to break ice and wedged it in between the rotor and the steering knuckle. A little leverage goes a long way, and it popped off on the first try. But Contour rotors are notorious for stickingb _ I'm about to attempt them myself. Most on this site will recommend liberal soakings of PB Blaster, humongous hammers, and patience.
