Source: eHow

Check the headlights on your Buick Lucerne every six months to make sure they are functioning normally. You can buy replacement bulbs at any auto parts store. You’ll need the part number on the bottom of the old bulb to get the correct fitment for the new bulb.

1) Open the hood of your Buick Lucerne and remove the electrical plug from the back of the headlight ballast. Push down on the release tab on top of the connector while simultaneously pulling the plug out of the ballast.

2) Turn the bulb counterclockwise and pull it out of the housing.

3) Insert the new bulb. Orient the bulb so that the base of the bulb and ballast sit inside the housing. There are two locking tabs on the side of the ballast. Orient the bulb and ballast so that when you turn the bulb clockwise it locks into the housing assembly.

4) Reconnect the electrical plug to the back of the headlight ballast.