Assign Task Custom Notification Properties

Does anyone have a problem with missing properties when creating an Assign Task with the UserServiceV2 in ES?    According to this document, there should be a way(Custom Email Templates property group) to override the default system notification settings.  How can the notifications be customized?

http://help.adobe.com/en_US/livecycle/9.0/workbenchHelp/help.htm?conte nt=000995.html