Choose Setup > System Configuration and click the Users tab. (If the Users tab is not visible, you must enter the master password.)
In the User list, highlight the user whose group membership you want to edit.
Select the Edit User button.
In the Edit User dialog, edit group membership for the selected user by marking or clearing the checkboxes in the Group list.
Users that are members of the $Unauthorized Users group cannot belong to other groups.
Select OK to close the Edit User dialog.