Replacing the headlamps on your 2003 Mitsubishi Outlander is a simple, but important, process. Driving your Outlander with faulty headlights can result in an accident or a citation from the local authorities. The Outlander uses single 9007-type bulbs for both its high beams and low beams, which can be purchased at most automotive parts suppliers.
Turn off the Outlander's engine, and raise the hood.
Remove the plastic cover at the rear of the headlamp assembly by rotating it counterclockwise, and pulling it off. This will allow access to the headlight bulb.
Twist the bulb socket counterclockwise in order to remove it from the headlamp assembly. Pull the old bulb out of the socket, and use a clean cloth to install the replacement bulb. Do not touch the glass of the new bulb.
Place the socket back into the assembly, and twist it clockwise. Reattach the plastic cover, and close the hood.