The MOD should have a "read me" file which provides some basic instructions on how to install it. We only provide assistance with setting up AutoMOD here. Support for a specific MOD needs to be sought wherever you downloaded it. In this case I believe that you're using WP-United which has a support board on their site.
Assuming that you already have AutoMOD installed, you would upload the unzipped MOD files to your phpBB board's
directory. Then go to the AutoMOD tab in the administration control panel and the MOD should be listed under the Uninstalled MODs section.
If you have any further questions take a look at the AutoMOD FAQ