You'll need to remove the rear rotors and determin what parts are damaged. You could be lucky and only need to buy new shoes but I'm guessing you're gonna need more than that. To remove the rotor, you will need to remove the calipers as well but you can do so without disconnecting anything, just remove the bolts, wiggle the caliper off the rotor, remove the torx bolt that is holding the rotor onto the hub and start looking at what's going on behind the hub.

Good luck and you have my number so feel free to call me Tuesday should you have any questions.