1. Open the hood.
2. Locate the headlight assembly you need to replace the bulb in.
3. Remove the protective cap from the back of the headlight assembly.
4. Disconnect the electrical connector from the bulb.
5. Remove the old bulb by turning it counterclockwise.
6. Insert the new bulb by turning it clockwise until it is secure.
7. Reconnect the electrical connector to the bulb.
8. Replace the protective cap on the back of the headlight assembly.
9. Close the hood.
Here are some additional tips for changing a headlight bulb in an 03 Lancer:
* Make sure you have the right bulb for your vehicle.
* Be careful not to drop the bulb.
* If you are not comfortable changing a headlight bulb, you can take your vehicle to a mechanic or auto parts store to have it done for you.
