The Pathfinder 3PP Pack is not made by Lone Wolf. It is made by volunteers from the Community, who use Hero Lab's built-in Editor to create new data files for products (such as various third-party supplements) that are not supported by Lone Wolf. However, to do this, some "basic" data packages are required, in order to avoid having to rewrite / recreate bunches of features that already exist: hence the need for somebody using this 3PP pack to have purchased the licenses for the APG, UM and UC.
To actually download the 3PP pack (and be warned when there are updates), see the first few posts of this thread:
http://forums.wolflair.com/showthread.php?t=51966