Rear Disc Rotor: Removal

Lift up the vehicle, and then remove the rear wheels.
Release the parking brake.
Remove the two mounting bolts, and remove the rear disc brake assembly.

Fig 1: Locating Disc Brake Caliper Assembly Mounting Bolts
Courtesy of SUBARU OF AMERICA, INC.
Suspend the rear disc brake assembly so that the hose is not stretched.
Remove the rear disc brake rotor.
NOTE: If the disc rotor is difficult to remove, try the following two methods in order.
1. Turn the adjusting screw using a flat tip screwdriver until the brake shoe moves adequately away from the disc rotor.
  
  Fig 2: Turning Adjusting Screw
  Courtesy of SUBARU OF AMERICA, INC.
2. If it is difficult to remove the disc rotor from the 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.