To free a Device-group from a Client attachment (without breaking all the client attachments):
1. Login to the AnywhereUSB Admin
2. Go to System > Configuration > AnywhereUSB Configuration
3. Go to the Port for the device-group you wish to free, change the port assignment to "Unassigned" & apply. This breaks the connection to the client AnywhereUSB Manager.
4. Wait until the Anywhere hubs refresh - not sure how long [ 30 seconds for a refresh? less than 6 seconds is too short]
5. Go ahead and and reassign the port to the device-group, and apply. The Group can now be used by somene else.