How do you replace spark plugs on mercury monterey?

To replace spark plugs on a Mercury Monterey, first ensure the engine is cool and disconnect the negative battery cable. Remove the ignition coil by unbolting it and disconnecting the electrical connector. Then, use a spark plug socket to carefully unscrew and remove the old spark plugs, and replace them with new ones, tightening them to the manufacturer's specifications. Finally, reattach the ignition coil, reconnect the battery, and start the engine to ensure proper operation.