Decommission a vCMP guest and reallocate its cores to remaining guests

We're planning to delete a vCMP guest that is not in use anymore, to reallocate its cores to other remaining guests. (Viprion C2400 with 3 x B2150)

I was wondering if any of you have already tried deleting a vCMP guest. Does this require changing it to Configured state before we can delete it? Is there also a need to delete its Virtual Disk?