I currently have ZCS 4.5.7 NE on a repurposed desktop running Ubuntu 7.04 (would be using LTS but it does not support our Intel Pro/1000 NIC). I'm going to be moving it to a new machine running on a hardware-identical server (Dell Poweredge SC series versus the Dimension it's on right now, same hardware in a different case) and upgrading to the latest 5.0 release at the same time.

What's the best way to do this? If I can migrate only the user data (e-mail, contacts, calendars) and not any of the server settings that would be preferred. There's some cruft in there that I'd rather not bring over from various experiments with LDAP.