Hello,
You can change the host-name of your server machine on which the Syamntec Endpoint Protection Manager is running.
Simply Reboot the server once you change the host-name and run the Management Server Configuration Wizard.
To run Management Server Configuration Wizard,
Go to Start-->All Programs-->Syamntec Endpoint Protection Manager-->Syamntec Endpoint Protection Manager Tools-->Click on Management Server Configuration Wizard.
Check this Article:
Renaming the machine on which Symantec Endpoint Protection Manager is installed
http://www.symantec.com/docs/TECH162062
Hope that helps!!