Powershell – way to rename a VM in System Centre Virtual Machine Manager 2012 R2

Why aren't you virtualizing your domain controller? Microsoft gives you the license for the virtual server provided your physical server is just doing Hyper V. There may be hacks to get the DC added, but it's so easy to just get it done right. Create a new VM. Promote it to domain controller. Demote the Hyper V server. Add the server to SCVMM.

It should be fine unless you're using the performance and resource optimization features, but I would not consider it a "supported" configuration.

Is there any reason you cannot remove them from the original SCVMM and then add them with the external server, with no period of overlap? If you're just trying to save time, near 100% of the capabilities of SCVMM can be accessed, although less efficiently, through a combination of the Hyper-V Manager and Failover Cluster Manager, in the case of clustered scenarios.