For the V6 engine, it is on the back firewall about just to the passenger side of the engine. It is about the size of a matchbox, it is black and sits on two rubber hoses that then attach to two silver lines. There is a three wire connector attached to it as well.
Remove the wire plug, then you can pull the hoses off the silver lines. Once free spin the hoses to free them from the plastic sensor, replace on the new one and put it back on the silver lines. Plug in the wire harness.
You may have to remove the battery cable for 5 minutes or go back to an auto parts store to have them clear the code.