The discs (rotors) on your Mazda RX8's disc brakes are made of reinforced carbon and make up an important system ensuring the safety of your car. When changing your brake pads, take the time to inspect your discs thoroughly, because your new pads will work most effectively only when applied to flat and smooth brake discs. Because of the weight distribution during braking, your front brake pads will probably wear out before your rear brake pads. However, even if all of your brake pads need replacing, you can do the job yourself as long as you have a moderate degree of mechanical ability and a few hours to spare.
Make sure the car is parked on a flat surface, Set the emergency brake and disconnect the negative terminal cable from the battery with a ratchet and socket.
Drain two-thirds of the brake fluid from the master cylinder using a turkey baster and store the fluid in a drain pan.
Remove the front hubcaps with a tire tool and loosen the lug nuts with the tire tool's lug wrench. Raise the front of the car with a jack, place jack stands beneath the axle on either side and slowly lower the jack until the car rests upon the stands. Remove the lug nuts with the lug wrench and remove the wheel with your hands.
Unbolt the two primary caliper mounting bolts, located on the top and bottom of one side of the caliper, with a ratchet and socket. Remove the brake hose from the caliper and slide the caliper up and off the brake rotor with your hands. Remove the brake pads from the caliper with your hands.
Retract the caliper piston using a C-clamp. Be sure to use one of the old brake pads between the C-clamp and the bottom of the piston for protection.
Insert the new brake pad, release the C-clamp from the piston, reinstall the caliper on the brake rotor and reattach the brake hose.
Reattach the wheels, remove the jack stands and lower the car with the jack. Repeat the previous steps for the rear wheels and brakes.
Refill the master cylinder with brake fluid and reconnect the negative terminal to the battery. Start the car and pump the brake several times to allow the brake pads to settle in place.