You have added more than 10 users to the User Management page of the appliance, however, only 10 are visible. Due to this fact, you are not sure what users are configured and do not know how to edit them.
By default the Grid Page Size (rows) for the SSLv appliance is 10. This means that 10 rows can be seen before you have to go to the next page. There is currently an open bug in which the "next page" icon does not work. As a result, any users over the amount of 10, cannot be seen. For example if you have 11 users configured, based upon the usernames' alphabetic order, one of the users will not show up in the GUI.
This is due to the fact that only 10 users are visible with the default row setting of 10 on the User Management screen.