The fog lights in a Volkswagen Jetta sit below the headlights. Depending on how much you use them, you may need to replace the fog lights on the same schedule as the headlights. Check the fog lights every six months; when you notice that a bulb is out, replace it immediately.
Open the hood of your Jetta and locate the electrical wiring running to the fog lights below the headlight housing.
Unplug the electrical connector running to the fog lights by hand. Squeeze the plug, paying special attention to pushing down on the release tab on top. Then pull the plug off the fog light ballast.
Turn the fog light counterclockwise and pull it out of the housing.
Insert the new fog light into the housing, and align the tabs on the fog light with the notches in the housing. Turn the light clockwise to lock it into the housing.
Connect the electrical plug to the light's ballast.
