Unlike passport renewal process, where you get emails to say:
We have received your old passport.
We have approved your application for renewal and will be printing your new passport.
We have printed your new passport and will be sending it to you.
We will also be sending your old passport back to you, but in a separate envelope.
When you get your new passport, you must sign it with a black ballpoint pen.
(I have omitted all the emails prior to the point where you send them your old passport.)