The 2004 Nissan Xterra sport utility vehicle uses a semi-sealed beam headlight. The halogen bulb is replaceable and can be accessed easily through the engine compartment, under the hood. Since you don't need to remove bumper or engine pieces, the replacement task can be done by the average DIY mechanic. Start this simple replacement process by going to your nearest Nissan dealership or parts replacement center to get the correct halogen bulb replacement.
Turn off the car engine and then pop open up the Xterra hood.
Use a wrench to remove the negative battery cable (the minus sign on the battery indicates the negative cable, and a plus symbol indicates the positive one). Twist the nut that holds the negative cable connector on the battery, and then pull the cable off.
Locate the headlight bulb socket and remove the electrical connector from it.
Turn the ring on the bulb retainer counterclockwise and pull it off.
Pull the headlight bulb out of the socket, being careful not to touch the bulb. If you are worried about getting your hands on the bulb, use some latex gloves.
Insert the new bulb, and then twist the ring back on the retainer.
Attach the connector back by pushing it into the back of the bulb until it snaps into place.
Reconnect the negative battery cable and close the hood. The light should now function properly.
