It is possible to change or delete the Group names using "Authorization Manager" in Microsoft Windows.
1) Make a backup of the 'AzManXmlStore.xml' file in the coordinator folder C:\program files\quest\change auditor\service
2) Start mmc.exe on the Coordinator server
3) File ==> Add/Remove snap-in ==> Authorization Manager
4) Right-click "Authorization Manager" and select "Open Authorization Store", XML-file option, browse to C:\Program Files\Quest\ChangeAuditor\Service\AzManXmlStore.xml
5) Drill down to "Role Assignments" and choose a role from
Operator Role
Administrator Role
AD Protection Role
Web Client Shared Overviews Role
6) Add/Remove/Rename the groups users
7) Log-in using the new account
Let me know if this helps