Move CALs between license servers on different domains

Hi,

We have two domains, Domain-1 and Domain-2.  All servers 2012 or 2012R2.   Formerly we only had RDP services on Domain-1 but now we need a limited number of clients on Domain-2 too.  Domain-1's RDS licensing server contains a number of CALs never used.  How can we disable or transfer these never used CALs to the new Domain-2 RDS licensing server?

regards Tor