After downloading presets, open Effects Lab Pro, and under the file menu, chose Import FXPreset Pack and then browse for the files you downloaded. They should automatically appear in the toolbox with the other effects presets.
Also, check out this link in the self-help forum, for additional help. And this video tutorial on the process may be useful as well, and is by Axeman himself.
To add to DV Studio, make sure you are downloading with an internet browser other than Safari. I wasn't able to import any of the downloaded presets because they were downloaded with Safari. Therefore, I got Firefox and my downloaded presets were able to be imported and ready to use in whatever projects I had.