You should first release the parking brake and lift the vehicle to support its rear for services and repairs to the cables in the 2500/3500 series. Turn the nut on the cable adjuster anti-clockwise and then take out both rear cables from the cable tensioner bracket. Open the clip at the right rear of the frame bracket and pull the cable away. Seize the tabs on the left and pull the cable up to fit into the frame housing mount. Take out the cable on the right rear wheel from the brake hose bracket and untie all the cable retainers from the axle. Following that, get rid of the rear wheels and drum set, unhook every cable from the park brake lever and get out the spring guide for the cables. Clip the cable tabs on each of the holders at the brake support plate and then remove the cables from the brake support plates. For installation, first add the cable guide spring and the brake drums. Withdraw the cable and put it through the brake support hole which will clip onto the park brake lever. Insert each cable housing through the hole in the brake support plate until the tabs lock. Give the housing a pull to check that it is secure. Fit the proper cable retainers on to the axle and send the right brake cable through the brake hose bracket hole. Guide both cables through the frame bracket, lock the left one by pushing until the housing retainer tabs clip and attach the clip to the right cable, making sure the right cable goes in the top and the left in the bottom hole. Next, attach the cables to the cable tensioner bracket and to the connectors on the wheel assembly, set the wheels in place, do the park brake adjustment and remove the blocks to bring the truck down.