I do not have access to server right now, but I remember that is an xml file under C:\Documents and Settings\All Users\Application Data (or Shared data) \ Qliktech\.... and the configuration is mentioned there. You can simply edit it and change the server name there. After change restanrt the services and you should be fine. Make sure to take a backup first of anything you change.
I will try to update correct path and file name later tonight when I have access to a v9 server.