Move the downloaded file to your /plugins directory
Change your configuration's values to what you see fit. "dbpassword" should be the only field you need to change.
Turn on your server, OverPermissions will download required libraries based on the configuration and then shut down the server.
Turn on your server again. If you see an error that says 'Failed to connect to the MYSQL database' it means your MySQL database isn't turned on or isn't configured correctly.
Start creating your groups with /groupcreate and adding permissions to them with /groupadd. (See Commands)
Current TODO list
Add importers/exporters for the major permissions systems