Unregistering a system via the Subscription Manager

I was curious as I can't seem to see how to do it, if there is a way to unregister an entitlement via the web GUI?

I am unloading alot of servers for a client, and part of my scripts are to do this, but it would be nice to validate and fix anything from the web interface.

Currently the only two methods I am aware of are for the linux applications, both the GUI and CLI tools.

Thanks,
Andrew.