EV - how to link vaults to new Exchange server

Hi Guys

I am trying to remove an old 2003 exchange server from EV. I have started following TECH50256 which states I have to move all linked mailboxes to the new servers before removing. I have a whole bunch of vaults which are not linked in AD and dont know how I will move these vaults as they dont have email accounts anymore.

Does anyone have any ideas how to deal with this?

Thanks in advance