A subuser is a secondary user of the Newsman account. It can be created only by the person who owns the email address with which the NewsMan account was created.
To edit a sub-user / secondary user, please go to My Account > User management, then click on the pencil icon on the right of the subuser you want to modify.
You can edit for the selected sub-user: the e-mail address, the password,the user type, the access to lists, and the 2-step authentication activation or deactivation:
To remove a sub-user, go to My Account > User Management, then click on the “X” icon to the right of the one you want to delete: