Will, you have DISK brakes, correct? And the calipers are off, so the park brake now has nothing at all to do with things, your rotors are just rusted onto the hubs.
There are two things you can do, and you'll probably have to do both of them.
First, find TWO ball-peen or similar hammers and a pair of protective glasses. Screw all the lug nuts on for several turns. Rest the head of one hammer lightly on the rotor surface directly between any two of the lug studs and hit the other end of the head with your second hammer. The whole point of using two hammers is to protect the lug nuts and studs - if you accidentally hit them with a hammer, you WILL damage them irreversibly; the first hammer is there ONLY to act as a means of transmitting the hammer impact to the rotor/hub face with minimal risk to the lug nuts & studs. Strike in that spot several times, fairly hard, then move to a spot between the next pair of lug studs and repeat. Go all the way around the hub face that way. SOMETIMES this is enough to get the job done - the hammer impacts transfer through the "buffer" hammer to the rotor face, then transmit through the rotor to the hub face, which "bounces" slightly but violently. That "bounce" gets transmitted back to the rotor, which vibrates in response, and that vibration helps free up the rust binding it to the hub. The hammers should be LIGHTWEIGHT (don't use six-pound hand sledges) so they can bounce, and you need to strike rather HARD with them (a sharp RAP that makes a crisp tapping sound).
If that's not enough to get the job done, Step 2 involves getting hold of two propane torches. PROPANE torches, the kind used for plumbing. They're cheap, they're common (you may be able to borrow a couple from neighbors), they're handy for lots of other things afterwards, and they're safe for everything you're going to do here. Light BOTH torches, adjust for about as high a flame as they can reasonably do without the flame "storming", and play the flames on the rotor area between the lug studs - one torch between two lugs, the other torch diametrically opposite, between two OTHER lugs studs. After heating for fifteen or twenty seconds, move both flames to different spots - still staying between the lugs. 'Round and 'round and 'round, just don't hold flame in any one spot for a great long time. You'll get tired, you'll get worried, keep at it.
The goal HERE is to heat the ROTOR, which will expand... and the center hole will grow slightly, while the hub center will not expand as fast because the rotor won't transmit heat to the hub as fast as the torches transmit heat to the rotor.
At some magical point, you'll hear a crisp SNAPping noise, which will be the rotor beginning to release. If you're lucky, it'll release completely and pop out from the hub. If not, keep after the torches until you hear a second SNAP. Have some heavy leather gloves handy to remove the rotor - it SHOULD be pretty hot by this time.
Magic, what you can do sometimes with torches. 8) I've had to do that to release WHEELS, even.
The snapping noise won't be the rotor cracking - it's just the sound of release, and doesn't indicate any damage.
Whichever way works for you - hammers or torches - let the hub cool down on its own, then sand the hub center (which registers the rotor's center hole) until you've got shiny metal there... then smear with a SMALL amount of anti-seize compound before you install the new rotor. SMALL amount, only enough to wet the metal... don't daub it on lavishly.