1. Park your Audi A4 on a level surface and turn off the engine. Allow it to cool down.
2. Open the hood of your Audi A4.
3. Locate the headlight assembly that contains the bulb you need to replace.
4. Turn the adjustment screw or knob counterclockwise to loosen the headlight assembly.
5. Remove the headlight assembly from the vehicle by pulling it straight out of its housing.
6. Disconnect the electrical connector from the back of the headlight assembly.
7. Press the release tab on the bulb holder and remove the old bulb from the headlight assembly.
8. Insert the new bulb into the headlight assembly and twist it clockwise to lock it into place.
9. Reconnect the electrical connector to the back of the headlight assembly.
10. Replace the headlight assembly into its housing and turn the adjustment screw or knob clockwise to tighten it.
11. Close the hood of your Audi A4.
