1. Park your BMW in a level area and turn off the engine.
2. Open the hood and remove the plastic cover that is located behind the front bumper.
3. Locate the two screws that hold the fog light in place. Remove these screws and then pull the fog light out of the bumper.
4. Behind the fog light, you will see the outside temperature sensor. It is a small, black sensor that is about the size of a quarter.
5. Disconnect the electrical connector from the sensor and then remove the sensor from the bumper.
6. To install the new sensor, simply reverse the steps above.