To migrate your address book(s) and sync settings, copy the contents of this folder:
C:\Program Files (x86)\Remote Utilities - Server\data
to the same location in the new installation. You can also copy the Logs and Stat folders if you need the logs.
As for relay, actually there's nothing to migrate there because the relay function is not supposed to save and keep any data. In this role the server simply forwards remote access packets.
Hope that helps.