Discussion room persistant names

I hava discussion room that was created with the ability to change names, but this ability was taken away recently. I have some users who are still coming in the room with the names that had alrady changed their diasplayed names, and these names are appearing to be persistant. Is there any way I can change or remove the names of the users to appear as they would normally fom the server(running down the number of users I am talking about would be too cumbersome, so I am REALLY hoping I dont have to catch up with all of them to do it in their spark clients).


I think there is no option to change their nicknames from the server.