SCCM 2012 EndPoint Protection migration

I have the old ConfigMgr 2012 name " BACKOFFICE" it is currently managing all the EndPoint Protection for all workstations/servers.

I now have new ConfigMgr 2012 called "SCCM"  I just installed ForeFront EndPoint Protection and configured the Custom Client Deviec EndPoint Protection to roll out to workstations. What is the best practice to remove old ForeFront EndPoint Protection client from old site name and install new one?

1. Do I have to manually uninstall EndPoint Client in control panel for each computer? or is there a way to just uninstall for all computers using the old COnfigMgr 2012 "BACKOFFICE"

Thanks for your help!