If it is an OVA deployment you could use the change password option which is available on reboot.
If you have WIndows or Linux installment you need at least mysql access to find or change the maintenance user email. If you don't you need to get in mysql first without changing the root password permanently, otherwise you break the GUI connection. There are how-to's available in the www. create a new mysql admin and document it. Change the email and go out. Use the forgot password function to get back in.