1999 Mercury Cougar Frozen Brake rotor

Hello!

A family member of mine has a '99 Merc Cougar. There is considerable wheel shake when the brakes are applied at high speeds. I pulled off the wheel (it took me about an hour of pounding and pentitrating oil to do so as it was frozen to the brake rotor), and noticed that the pads had plently of life in them, but the rotors showed signs of delamination. I attempted to pull off the rotor, but it is also frozen on. What is an approved way to remove a frozen rotor without damaging anything? Can I use a gear puller? I aready tried with minor pressure, but I can't seem to budge the rotor.