How do you change the spark plugs on a 1999 infiniti qx4?

To change the spark plugs on a 1999 Infiniti QX4, first, ensure the engine is cool and disconnect the negative battery terminal. Remove the engine cover and the ignition coils by unscrewing their bolts and gently pulling them out. Use a spark plug socket to remove the old spark plugs, then install the new ones by hand to avoid cross-threading, and torque them to the manufacturer’s specifications. Finally, reattach the ignition coils and engine cover, and reconnect the battery.