Regretfully, we're unable to change the email address on your account. However, the solution is quite easy - all you need to do is create a new account, using your new email address.
You can create a new account at this link:
https://www.shoppingsquare.com.au/checkout_ebay.php
We are working on having this updated so you can easily change your address without the need for a new account so we'll let you know when this changes.