NW5.1 sp8 -> two servers, one with Groupwise 6.5

All is working fine, and I'd like to add a Netware 6.5 server into the tree.
Is there a "how to" with instructions? Could the 6.5 server be intalled
into a tmp tree, then DS removed and the server added into the 5.1 tree?

The 6.5 server is primarily for redundency - and to allow specific users
access to their files.