If you must retain your production catalog, then the answer is, I don't think that you can. The problem is that hostnames are deeply embedded throughout the catalog and image database. Our Veritas sales rep "claims" that they can do it, using their consulting services,however, evey tech I have spoken to over there is dubious.
If you don't need to retain your catalog, you could build your new master server on a different machine, and keep the existing master server intact until the last image written on it expires. You would, in effect, start from scratch with a brand new catalog. This way, if you need to do restores, then you could fire up your old system,query it for the media you need to perform a restore, and import the media/images that you need into the new system.
This would require some planning, in terms of scheduling the entire migration of clients, unless you have the capacity to take full backups of all of your clients in one cycle.
Another "hack" would involve creating a CNAME for your old server, which points to your new server, but, that's definitely not ideal.
HTH,
Steve