I searched everywhere on how to change an O2 sensor on a liberty and found nothing, so here's what I know.
I tried getting the special socket to get my old o2 sensor off (driver side, after cat), but found that either the socket I had was too long, or Liberty's are not meant to have the o2 sensor taken off using that socket. It took a long time to not only get the socket on the sensor, but to figure out how to get any movement out of the wrench was near impossible. Long story short, I used a 7/8 wrench which was all that allowed me to get a grip on the sensor and get enough torque to move it.
I'm only posting this because it would have saved me about 2 hours of messing with that socket if I had read something like this.