Decommission the Source Domain
Applies To: Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2
Applies to: Active Directory Migration Tool 3.2 (ADMT 3.2)
After you have migrated all the objects from the source domain to the target domain, including all the computers and member servers, only the domain controllers remain in the source domain. To decommission the source domain, remove Active Directory or Active Directory Domain Services (AD DS) from the domain controllers in the source domain.
Migrate the domain controllers from the source domain to the target domain as member servers. If necessary, depending on the new role that is planned for the servers in the target domain, use install Active Directory or AD DS on the member servers to return them to domain controller status in the target domain. Run security translation on domain controllers, if resources reside on the computer that will be used as the new domain controller.