Rear Disc Rotor: Removal

Lift-up the vehicle, and then remove the rear wheels.
Pull down and release the parking brake.
Remove the two mounting bolts and remove the disc brake assembly.

Fig 1: Identifying Disc Brake Assembly Mounting Bolts
Courtesy of SUBARU OF AMERICA, INC.
Suspend the disc brake assembly so that the hose is not stretched.
Remove the disc rotor.
NOTE: If it is difficult to remove the disc rotor, perform the following two methods in order.
1. Using a flat tip screwdriver, turn the adjuster until the parking brake shoe is apart enough from disc rotor.
  
  Fig 2: Identifying Flat Tip Screwdriver, Adjuster, Back Plate And Cover
  Courtesy of SUBARU OF AMERICA, INC.
2. If it is difficult to remove the disc rotor from hub, drive an 8 mm bolt into the threads B of the rotor, then remove the rotor.
  
  Fig 3: Identifying Disc Rotor Thickness
  Courtesy of SUBARU OF AMERICA, INC.