Change RHEL 6 Workstation to Server

Hello All,
My IT manager recently made a mistake in re-ordering the subscription for our sluster of systems and ordered RHEL 6 server subscriptions instead of work station subscriptions. I tried to have him change the subscrition to wokstation, but Redhat would not do that. Is there any way to have the system registration type change from Workstation to Server without a complete system reinstallation?

Thanks,
Karl-Heinz Konrad