Change Wordpress MU Address

I am working on moving to a new server, but I need to test out our installation before we move it completely over. I have made a duplicate copy of the data and the sql database on the new server, but I need to change the URL for the whole installation (and the blogs) for a while on the test server so I can resolve it.

On regular wordpress you can go into the SQL database and change a couple of entries and it will resolve with the new address. Can we do something similar with wordpress mu? If so, what entries to I need to change?

Thanks for any help you can offer