If you are facing the engine bay (hood open, standing in front of the Jeep); the PCV is on top of the Right valve cover (aka as Drivers side).
To replace the PCV:
(you will have to remove the small black plastic block which is darn near on top of the PCV valve. The spark plug wires go into this block. You will need to remove this block first. It is only held on by two 10mil bolts.
Get a 10mm (iirc) socket
Unbolt the two bolts which hold this black block to the valve cover assembly.
You will now see the breather hose from the manifold into the valve cover
Pop off this breather hose from the PCV
Some say to use a zip strip to attach to the "crown" of the PCV and pull up. That didn't work for me. I simply used a needle nosed pliers to pull the PCV straight up and out. Super easy!
Push the new replacement PCV into the socket firmly
Reattach the breather hose to the top of the PCV
Insert the two bolts to remount the black spark plug box
Drive and wave to all the hot chicks.
Lastly, when I switched to 5w30 and changed the PCV, my oil usage stopped. I have an early 2008 (built in sept 2007). I bought the Jeep brand new, broke in engine correctly, changed oil religiously with full synth Mobile1.
The Jeep currently has 48,000 miles on the clock. It performs well.