VMS Help LICENSE, UNLOAD, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    LICENSE UNLOAD affects all units for a single product even if
    the loaded units are combined from multiple licenses. In such a
    case, you cannot unload the units from a single license. You must
    unload all the units.

    You are not required to unload a loaded license before modifying
    data in the License Database. To maximize product availability,
    modify licenses in the License Database first, and then load
    the changes by entering a LICENSE UNLOAD command followed by a
    LICENSE LOAD command.