How do you replace the headlight bulb located on a 2003 Jaguar XJ?

To replace the headlight bulb on a 2003 Jaguar XJ, first, ensure the vehicle is turned off and the keys are removed. Open the hood and locate the back of the headlight assembly; you may need to remove the cover or unscrew any retaining clips. Disconnect the wiring harness from the old bulb, twist the bulb socket counterclockwise to remove it, then insert the new bulb into the socket, ensuring not to touch the glass with your fingers. Reconnect the wiring harness, secure any covers or clips, and test the headlight to ensure it works correctly.