I was never able to find a document, but here's what I did. It worked perfectly.
1. Build out new server with temporary name & IP address. Make sure all connected backup hardware is configured and working.
2. Install Veritas NetBackup on new server (plus latest MP), same versions as original Master Server.
3. Stop all NetBackup services on both master servers
4. Copy entire contents of VERITAS program directory from old server to new server, overwriting everything. (If you've relocated any catalog info, copy it also.)
5. Export all Veritas registry keys on old server, and import them on new server.
6. Shut down old server.
7. Rename & re-IP new server to match old server.
8. Start all Veritas services on new server.
9. Verify all functionality.
I did this with NBU 5.0 MP4, and it worked perfectly (which surprised me, actually). In case of a disaster, you still have the old server to revert to, if necessary.