If replacement is integrated, which is usually the case when the calipers exhibit fluid leakage, then replacement is advised over overhaul. New and factory rebuilt units are exchange only so this job is very simple. Calipers should always be replaced in pairs because never is an appropriate time to change just one of the two. First, they ought to unscrew the front or rear wheel lug nuts, lift the car, and put it on jackstands, placing an obstacle under the opposite wheel before removing the front or rear wheel. After that unscrew the banjo bolt, separate the brake hose from the caliper and dispose the sealing washers, as with the new ones that are recommended to be used. This opens up the brake hose to prevent undesirable materials from getting into the system while preventing brake fluid wastage as well. Next, to do that, undo the caliper mounting bolts and then take off the calipers from their bracket. For installation, the process follows the reverse of the above mentioned removal procedures, and is concluded by tightening the caliper mounting bolts to the recommended torque, and the wheel lug nuts as well. There is a banjo bolt on the brake hose end to connect it to the caliper; make sure you replace the sealing washers. Last but not the least, master cylinder to bleed the brake system and check for any leakage around the hose connections and the brakes must be tested thoroughly before moving the car back to its normal use.