[papajam]

There are two flathead machine screws that hold the rotor onto the axle. They just might be a little hard to see because of dirt/rust etc. Remove the screws. Then take a 20 oz. (or so) hammer and strike the rotor on the same face that the screws go thru (like you're hitting the rotor ONTO the axle). Do this in the 4 spaces between the studs and the rotor will pop right off.

Sounds like the caliper pistons need a little persuasion. Place a piece of wood between the pistons and have a helper pump the brake pedal while saying 'resistance is futile'.
When reinstalling, the notched side of the piston that the pad touches, faces away from the direction of rotor rotation.