Thread:Vorknkx/@comment-26005008-20150729053117/@comment-1496755-20150729054246

It's installed just like the game itself - you insert the CD into the drive and install it. It's a separate product, just like Quake's mission packs (except that it also has its own executable, whereas Armagon and Dissolution consist only of PAK files).

The only requirement is that Hexen II is upgraded to v 1.11, but if it's not, the PoP installer will do that automatically, I think.

After installation, you can find and download the 1.12a patch to upgrade PoP a little further (to fix a few bugs here and there).