Therea are at least two ways to achieve it.
Proxy shares from old to a new server
[global] host msdfs = true [Share] msdfs root = true msdfs proxy = \\newserver\Share
Shutdown old server and overtake its shares with alias
[global] netbios name = newserver netbios aliases = oldserver [Share1] ;same Shares as on the old server [Share2] ;same Shares as on the old server