[ovirt-users] Unable to remove system roles from Everyone group

I opened Everyone group and added system role UserRole and realized now that everybody can see all VMS which is not good. I tried to remove the role from the group but got the error "Error while executing action: It's not allowed to remove system permissions assigned to built-in Everyone group" Looking into Ovirt forums I see that this change should be made through the engine database but I was not able to reach that part. Can someone help me out how to remove the system role from Everyone group? or at least reset the group?