Oxygen sensor - Service engine soon light

The last 3 times (about once a year) my service engine soon light came on it was a piece of carbon on my oxygen sensor. How do I do this job myself were is the oxygen sensor located?

97 grandprix gt 120k

It is located on the exhaust system, there are two of them, one after the exhaust manifold and the other after the cat converter. Lift the car and place it on jackstands to take a look at both sensors. Make sure you do this job in the morning so the exhaust is completely cold or at least let it cool down for a while before you touch it ;)

Good luck!

You will need an O2 sensor wrench to get the Sensor out properly. They are readily available at most parts stores.