2004 Chevrolet Impala Owner's Manual - Page 316

6. Turn the old bulb counterclockwise and remove it from the retaining ring by gently pulling it away from the headlamp. 7. Remove the electrical connector from the bulb by raising the lock tab and pulling the connector away from the bulb's base. 8. Install the electrical connector to the bulb. 9. Install the new bulb by inserting the smallest tab on the bulb base into the matching notch in the retaining ring. Turn the bulb a quarter-turn clockwise until it stops. 10. Reverse Steps 1 through 5 to reinstall the headlamp assembly. Then, check the lamps. 4. Gently pull the headlamp assembly away from the vehicle and remove the electrical connector. 5. Remove the round dust caps to gain access to the bulbs. 5-54