Exchange Server 5.0 Migration

Exchange Server 5.0 Migration!
I have Exchange Server 5.0 which currently run under P233 with Windows NT4.0. My boss want to migrate the exchange server 5.0 accounts from the old system to the new one. The new system has Windows NT 4.0 Server and Enchange Server 5.0 installed freshly, What steps should I need to do next. Thank you!!