Migrating SEPM 11.x. to SEPM 12.x(Different hostname and IP address)

Hi Guys, this is first time i'm meddling with Symantec Anti virus. Following is the situation. 

The current SEPM(11.x) server is running low on resource and hence they prepared another server with new host name and IP. The old SEPM server will be decommisioned. The new server will be running on SEPM 12.x

My concern is as following: 

1) Can i backup the policies and exclusion to the new server and how do i that as SEPM versions are different. 

2) Since the new server is on new Host and IP, the old agents won't be communcating back, Does this mean this is a fresh installation? and this installation will overwrite the current SEP agents in endpoint or the old SEP agents need to uninstalled before installing the new SEP versions.