Once you get access to the drive working across network, make sure you can reliably get to it from Windows Explorer (the file explorer, NOT the internet browser). Once that's done you need to update all of your media entries in your MC library to point to the new file location. Or reimport all of them. Depending on how much media you have it might be easier to just reimport it. I *think* reimporting will actually preserve all of the data including play counts etc. Maybe someone else can confirm?
If you want to update all of the media paths, you'll probably want to use the Move, Rename, and Copy tool. It's under: Tools > Library Tools
To do this particular job, you probably want to run the tool in Update Database mode, and then use the Find and Replace option at the bottom of the box. Some documentation here:
http://wiki.jriver.com/index.php/Rename,_Move,_and_Copy_Files#Find_.26_ReplaceBe sure to test on a few files first. ...and do a DATABASE BACKUP before you start!! Good luck!
Brian.