Spent 30 min replacing PCV valve on my 2002 WRX today.
Tools you need:
12mm socket & wrench
PCV valve from autozone: PN PCV1142
First, you have to remove TMIC and it can be done by following steps I posted here:
Once TMIC is removed, please follow these 'simple' steps:
Disconnect blow off valve recirculation pipe from BOV and pull it away so that you can reach PCV easier.
Disconnect this hose (small amount of coolant may spill out)
PCV is located here:
Simply pull the hose away to expose PCV:
Using 3/4" wrench, remove PCV: