1) Go and buy a copy of AHD.
2) install it over your copy of V2.
3) Patch it to 2.31
4) Download APD 3.1.7
5) Delete any existing PDM folder inside the Victoria 2\Mod folder before installing.
6) Extract the zip to your Victoria 2\Mod folder.
7) Go to the My Documents\Paradox Interactive\Victoria 2\PDM folder and delete the map cache there.
8) Fire up the launcher, select 'A POP Divided' from the bottom-left menu, and press 'play'. The Checksum generated may not match that above first time you play, but should on subsequent launches.