To change the e-mail address you used to register your account with us just follow these steps:
Log in to your customer’s portal: https://billing.stablehost.com/clientarea.php
Go to ‘Hello <Your Name>! ‘ and click on ‘Edit Account Details’.
Enter your new e-mail address.
Click on ‘Save Changes’.
Important: This e-mail address will work as your customer username, so the next time you need to log into the customer's portal you'll have to remember this change.