To get the best out of the contents, you will need to purchase True-VDB first. This also comes with 10 assorted assets, but also provides the user interface and controls needed to import packs, update contents/categories, swap between materials etc. 

You buy and download this pack, and then unzip the .ZIP file. Inside are several .7z files, leave these closed. Open True-VDB and head to the user prefs, click "import pack" and then select one at a time, the packs inside this product. They can take a few minutes to install, so do not close Blender during this process.

If you wish, however you will not get the best experience out of this, and we have not designed this pack to be used outside of the addon. So if you cannot get it to work, then we aren't responsible for that, and we will not agree to a refund.