Hello,
In your case, where If the new SEPM server has a different IP and host name, there are two alternatives:
1. Use replication to install a new SEPM and keep the policy the same with old SEPM. See "How to move Symantec Endpoint Protection Manager from one machine to another"
http://www.symantec.com/business/support/index?page=content&id=TECH104389
Note: Replication is an option, if you do replication and remove the old server that is the Primary SEPM, in future if you want to do replication you will not be able to do so.
2.Follow disaster recovery method & Create a new MSL.as per following
a) Follow "Best Practices for Disaster Recovery with Symantec Endpoint Protection" (see Related Articles below) to backup and reinstall SEPM on MACHINE_2
b) Log in to the old SEPM on MACHINE_1
c) Click Policies > Policy Components > Management Server Lists > Add Management Server List
d) Click Add> Priority and a new Priority would get added named as "Priority2"
e) Add MACHINE_1 under Priority 2 and add MACHINE_2 under Priority 1, and assign this New Management Server List to all the groups.
f) Clients will then move from old SEPM to new one gradually
g) Stop the "Symantec Endpoint Protection Manager" and "Symantec Embedded Database" service on MACHINE_1 to verify whether all client now report to the new SEPM on MACHINE_2
h) Once verified that all the clients are reporting into the new SEPM, and have moved away from the old one, proceed to the next step.
i) Uninstall SEPM from MACHINE_1
OR
Install a new fresh SEPM, then use the Sylink.xml file to establish the communication between new SEPM and the existing SEP clients with the help of Sylink replacer tool.
This option is effective if having limited number of clients in the network.
I hope it will help you.