Migration advise

We have a server with around 75 users and want to make downtime to a minimum.

We have zextra's with the backup module and want to rsync the data over to the new box which has exactly the same name and version of Zimbra.

What is the best way going about this. We were wondering if we could do the main rsync to the new box and restore, then may be some sort of incremental restore afterwards.

Can zextra's do this and what's the best way going about it.

Many thanks

Glenn