Top of page. Replacing the Solenoid. Solenoids are located either on a panel in the engine compartment or on the starter itself. To replace a panel-mounted solenoid: Remove the cable from the battery, the cable to the starter, and the small wire or wires, being sure to note their exact locations.Remove the mounting screws and lift off the solenoid.eplacing the Starter. Remove the battery/starter cable attached to the starter-mounted solenoid or to the starter. Remove any other wires attached to the solenoid if it is starter-mounted. Note the wire positions so you can replace them correctly.