Multi-DB Plugin help Please

Hello, I am trying to install the Multi-DB Plugin for my Multi-site, which is very small for the time being so there aren't a lot of files to get in the way. I downloaded the plug-in and added the databases to the correct place. Everything with that went great, however, now I have thousands of databases with no user or password...bummer because that's required to continue in the installation process. I REALLY don't want to have to go in and give each individual database a user and password. That would take days. Is there any way around this? How did you do it for your site? Or am I confused about how to do this in general....? All help is greatly appreciated!