Start by loosening the wheel nuts, lift the car using a jack, and prop it up on safe jackstands. Put on the lug nuts to keep the disc in position while you work, and turn off the parking brake before touching the back brake disc. When raising a vehicle with electronically adjustable air suspension, make sure you switch off the height control before starting to lift. Reach the caliper, leaving its hose connected, and fix it off to the side with wire. Undo the bolts holding the caliper bracket and pull the bracket off. Scrutinize your brake disc for defected lines and annoyances; just mild scratchings are usual, but any trouble bigger than one thirty-second of an inch warrants taking the disc out for repair. Look on both disc faces for signs of shaking while you brake. If so, the disc has a roundness issue. Examine disc runout by putting an indicator dial at 112" away from the outer edge and measuring while turning, making sure the maximum value stays below allowed limits. Getting new discs when you replace the brake pads helps keep everything working well. Sandpaper the disc from top to bottom, and then back, until all its glaze is gone. Check not to machine the disc below the built-in minimum refinishing thickness, which you can measure with a micrometer. Take off the wheel nuts securing the disc, then easily slide the disc off the hub. If parking brake shoes are blocking your way, remove a pin and shift the shoes into place. Put the new disc on the threaded studs and mount both the caliper bracket and caliper. Then tighten the bolts to the correct torque settings. After dealing with any parking brake shoe interference while installing, put the wheel back on and attach the lug nuts. Lower the vehicle, bolt down the lug nuts at the required strength, then test drive. Close the brake three times to help the brake pads touch the rotor.