Park the polo on level ground, turn the engine off and apply the parking brake. Pull the hood release handle and move to the front of the car.
Lift the hood and remove the master cylinder. Remove one-half of the brake fluid inside the reservoir with a syringe.
Loosen the lug nuts on the rear wheels with a tire iron. Place the jack beneath the frame at the back of the Volkswagen and lift the back tires off the ground. Rest the rear axles of the Volkswagen on two jack stands. Remove the lug nuts and take the rear wheels off.
Reach behind the brake caliper to locate the caliper mounting pins. Remove the pins with a 12 mm socket and ratchet. Lift the caliper from the brake rotor and suspend it above the wheel assembly with a bungee cord or wire coat hanger.
Remove the rear brake pads from the slots in the caliper bridge. Inspect the caliper bridge and rotor for damage and significant wear. Replace the rotor if it is warped or badly scored. Scoring of the rotors can lead to break failure and will prematurely wear the new brake pads
. Place new brake pads into the slots of the caliper bridge.
Attach the piston depression tool to the caliper. The tool will fit over the back side of the caliper and against the piston inside. Twist the tool's handle to force the piston into the side of the rear caliper. Remove the tool once the caliper piston is totally depressed within the caliper.
Replace the caliper onto the caliper bridge and screw in the caliber mounting pens by hand. Replace the rear wheel onto the wheel bolt and screw on the lug nuts.
Repeat the process for the other side of the rear of the polo. Lift the rear end of the vehicle with the jack and remove the jack stands. Lower the rear tires to the ground and tighten the lug nuts with a lug wrench.
Return to the engine compartment. Remove the master cylinder cap and check the level of brake fluid. Place a funnel into the container and fill the reservoir with brake fluid as needed.