How do you change an O2 sensor?

Wait until the car is cooled down. To change an o2 sensor you must have an 7/8 inch wrench or have an o2 sensor wrench. After finding the correct tool for the application you then jack up the car in most cases. Find The o2 sensor in the exhaust system most likely at the front of the car behind the front wheels about 2 feet in. Loosen the o2 sensor with the wrench and unscrew. Reverse process for installation.