It is possible to change your main account email via Account > Account Details screen.

Please note! 

You are changing the main user's email, make sure that the email has not been added as a secondary user under Settings > User Management. The Super admin option needs to be unticked for the user's email before deletion, otherwise the Delete button will be grayed out.

In order to retain all your tickets in Support Center (, you need to login to the Support Center via at least once prior to the email change.