We have a 2003 Domain with 2003 R2 File Servers

Currently using DFS on the 2003 File Servers

Looking to expand our storage.

How can we install a new 2008 File Server, move all the 2003 Data from the 2003 to 2008 file server with the larger storage?

Is it a matter of just adding the 2008 server as a new target and having the data replicate off?

I've seen mentions of Robocopy and the FSMT from microsoft?

What is the best way to accomplish this?