Starting with the engine cover removed. Hope this helps...
NOTE: PCV & Check valve are 2 different parts!
You need to unscrew the cover & remove it to get at the old PCV valve. On my car the check valve and fuel line were in the way & once the cover was unscrewed off I couldn't wiggle the cover around them to get it out.
Biggest PITA is releasing all 4 tabs to get the Check valve out of the way. Used a long feeler gauge & 2 picks.
Used a 1/2" wrench - it fits tighter on the hex than a 13mm.
Cover removed, Nipple of old valve must be pulled out.
I grabbed it w/ plyers & pryed it out of the hole.
Here's what the OEM looks like. The threads on the left side do not screw into anything. That's why it can be pulled out w/ plyers. (WTF must be a BMW leftover part) The o-ring is NOT used w/ PCV2.
Sorry for the bad pic, but here's Rob's PCV2 in the cover. Just screw it in & reassemble what you removed!