I expect that your rear ebrake cables are rusted frozen. I have seen this happen several times over the years and I've never had success in freeing them up. If you could take them off and soak them you might get them freed up, otherwise it's new cable time.

To get the rotor off, rotate the rotor until you can see the star wheel behind one of the lug bolt holes. It will probably be slightly forward toward the top of the bolt pattern. Turn this starwheel with a screwdriver to loosen the brake shoes for rotor removal.

Good luck,