Disconnect the cable from the negative battery terminal. For 4.2L V6 models, disconnect the electrical connector from the ignition coil, then disconnect the spark plug wires from the ignition coil. Remove the ignition coil mounting bolts and take the coil out from the valve cover, with installation being the reverse of removal. For 3.5L and 3.7L V6, and all V8 models, this procedure applies to all eight ignition coils. Disconnect the electrical connector from the ignition coil by depressing the release tab and pulling off the connector. If removing more than one ignition coil, mark each electrical connector with its corresponding coil to avoid mix-ups during reassembly. Remove the ignition coil hold-down bolt, then grasp the ignition coil firmly and pull it straight up. Inspect the condition of the rubber boot that insulates the connection between the coil high-tension terminal and the spark plug; if it is cracked, torn, or otherwise deteriorated, replace it. To disconnect the boot, simply pull it off the coil, ensuring not to pull off the spring that carries the current to the plug. Prior to installing the coil, coat the interior of the rubber boot with silicone dielectric compound, with installation otherwise being the reverse of removal.