Your login email can be changed from the Settings page. Click on Settings in the left hand navigation bar.
Within Settings, click Security where you can change your login email as well as reset your password, and set up an app authentication. On the Security page, enter the new password you'd like to use in the Reset Password section then click the Save button.
Note: If you do not click the Save button and navigate away from the Settings page, then your email address will not be updated.