I would like to add a bit of information here on replacing the 3.0l V6 PCV valve. My PCV valve was stuck in there good after 205,000 miles and never being replaced. Previous owners... The manuals suggest using a long pliers, but it would not unscrew from the oil separator, no matter how hard I tried, but this did the trick.
If you remove the air filter housing and air plenum (where the MAF is mounted to) off of the throttle body, there is enough room to take a Deep Wall 7/8" (I think) 12 Point socket with a 12" wobble extension and remove the PCV. The 12 point socket is the key to getting over the valve, as it has a square flange on it that makes it easy to remove like a bolt. It unscrews about 180* then pulls straight out. There will be resistance from the O-ring, so you may have to then pull it straight out with a pliers.
Hope this helps!