The PowerShell ActiveDirectory module for Windows Server 2012 has a new cmdlet that helps move the FSMO roles. It is Move-ADDirectoryServerOperationsMasterRole. I know it is a long one. That is why we have tab completion. To move a FSMO role, just type:
Move-ADDirectoryServerOperationsMasterRole –Identity <TargetServer> –OperationsMasterRole <RoleName>
It looks very easy, but the instructions lack the names of the roles. Here they are.
You can find these if you look at the examples in the help file. I transferred all my FSMO roles using this command:
Move-ADDirectoryServerOperationMasterRole –Identity <ServerName> -OperationMasterRole SchemaMaster, DomainNamingMaster,RIDMaster, InfrastructureMaster, PDCEmulator