You cannot transfer administrative authority to someone else.
However, you can change the administrator's email address and password, so that someone else can log in and use. Here is how to do it.
How to change email address and password
(1) The administrator should click on his/hers' user account and click [Profile setting] from the menu bar.
(2) Editing screen will be shown in [Manage Operator], change [Email address] and [Password] from there.
(3) Click on [Update].