I just came back from 6 months abroad... I come to find a new P2ATC version! Awesome!
I purchased, no problem, but the AIRAC is 1801. How do I update the AIRAC?

Thats stupid question 1. Stupid question 2 is, Am I safe to remove P2ATC Version2?

You can leave V2 installed as V2 and V3 don't interact.  V3 is an Early Access version and has more bugs than V2 at the moment, so you may want to have V2 to fall back on.  If you like, you can remove V2 at any time.

You will need a Navigraph data subscription to be able to update the data.  You then can point the FMS Data Mgr to your V3 Installation folder and do the update.  That will place the latest V2 data into the V3 data  folder.  

Then follow the instructions in the Quick-Start First Flight video to do the Data Conversion to V3 data format.

Dave