Place the 7/8" (22 mm) socket around the O2 sensor. Use a ratchet and 6" extension to loosen and remove the sensor.

Place the socket on the sensor without the ratchet in the way. Once the socket is in place, reattach the ratchet and loosen.

The sensor is behind the exhaust, up against the firewall. Having a headlamp, or a friend who can hold a flashlight, is a big help. The red lights in these photos are cheap magnetic lights!