Can't unauthorize build agents on an old server

Hi!

Is there a way you could unauthorize build agents on an old server you can't access anymore due to disk-failure?

We have restored a BU on a new server and can't access the old one.. The new one is running on the same licenskey as the old one, but we are unable to reuse all three licenses as we didn't have the chance to unauthorize two of them before the disk failure.

Regards/Jean