Chrysler Repair: how to replace back O2 sensor, negative battery cable, chrysler sebring

Question
Kevin we have 2001 chrysler sebring lx 4 cylinder my engine light came on , so we asked autozone to check it out they said its O2 back heat sensor my husband bought the sensor but he is not sure how to replace it, i would appreciate if you could walk him through

Answer
REMOVAL - DOWNSTREAM 1/2 4 CYLINDER
The O2S is located in the side of the catalytic converter (O2 SENSOR DOWNSTREAM 2/1 4 CYLINDER).

WARNING: THE EXHAUST MANIFOLD, EXHAUST PIPES AND CATALYTIC CONVERTER BECOME VERY HOT DURING ENGINE OPERATION. ALLOW ENGINE TO COOL BEFORE REMOVING OXYGEN SENSOR.

Remove the negative battery cable.
Raise and support the vehicle.
Disconnect the wire connector from the O2S.
CAUTION: When disconnecting the sensor electrical connector, do not pull directly on wire going into sensor.

Remove the O2S. Snap-On oxygen sensor wrench (number YA 8875) may be used for removal and installation.