Always take off the negative cable first and reconnect this last because touching the positive terminal with the metal you used to loosen the clamps on the insulation could cause a short circuit, the same applies with the post terminal; even when replacing the cable for the terminal that was taken off first, take off the negative cable first. Remove the old cables from the battery, follow every cable to its other end and remove it, and keep noting the position of every cable so as to rectify them when fixing the new ones. To extend for cables, be sure to bring along the old cables in case replacement is required for new ones must match the original parts. Simply scrub the threads of the solenoid or ground connection with a wire brush to eliminate rust and corrosion, you are recommended to put a thin layer of battery terminal corrosion inhibitor or petroleum jelly to prevent the threads from rusting again. Connect the cable as will be either to the solenoid or ground connection and tighten the mounting nut or bolt. Before tightening the nut after a new cable to the battery terminal, make sure that the new cable does not go to the battery post by extending it.Connect the positive terminal of the battery first to the new cable and then the ground cable to the negative terminal of the battery.