Download the .zip file and extract the materials.p00 file to the common folder of your Risen 2 installation.
This is by default C:\Program Files (x86)\Steam\SteamApps\common\risen 2\data\common\
I recommend to delete the ximg files of the previous version from your AppData\Risen 2\Config folder. Though this is not mandatory since both versions are compatible.
|No POM Mod (previous version)||39.6||31.5||51.5|
|No POM Mod (new version)||40.3||33||52.5|