When coming to work, learn about the risks of hydraulic fluid and asbestos dust. In order to loosen the rear wheel, chock the front ones, jack -lift the back of the car and place it on axle supports. Reduce loss of fluid by taking out the master cylinder reservoir cap and sealing it with polythene or brake hose clamp. Wipe the surrounding of the union on the caliper and loosen the nuts. Take the caliper off the brake pads, unscrew it off the flexible hose and take it out of the vehicle. Brake caliper handbrake mechanism can not be overhauled, in case of faultiness or leak, then it will be necessary to change the caliper assembly. Wipe dust and dirt on the bench, but not breathing in. Be careful not to tear the dust seal with a small screwdriver when opening it and then use circlip pliers to rotate the piston anti-clockwise and then withdraw it by hand. Remove the piston hydraulic seal(s) without breaking the caliper bore, the guide pins, and remove the gaiters of the guide sleeve. Clean all parts using methylated spirit, isopropyl alcohol or clean hydraulic fluid, but not mineral based solvents. Inspect all parts of wear or damage, especially, the cylinder bore and the piston, which must be replaced in case of scratches or corrosion. Get repair kit when required and replace all the rubber covers and dust covers and caps as it must not be used again. Care should be taken to ensure that all parts are clean and dry upon re-assembly and which a very thin layer of brake fitting paste on the piston, seal and bore. Install the new piston seal followed by the new dust seal with fingers and then re-attach the piston assembly by turning clockwise and then fully re-tracted. Insert the dust seal, grease the guide pins, install new gaiters, and make sure that they are in the right place in the grooves. Put fresh hydraulic fluid in the caliper by loosening the bleed screw and pumping until all the bubbles are cleaned out. Attach the screwed caliper to the flexible hose union, reattach it to the brake pads and tightly screw the brake pipe union nut. Take out the brake hose clamp/polythene of the fluid reservoir and bleed the hydraulic system, in most instances, it is just necessary to bleed the corresponding rear brake. Connect the handbrake cable to the caliper, re-adjust the handbrake, re-fit the roadwheel, lower the vehicle, then tighten the roadwheel bolts to the required torque and test the level of the hydraulic fluid when done.