Log into your WebAura Client Area (https://portal.webaura.com/clientarea.php)

Click on "Services".

Click "Manage Product" on your active shared hosting service.

Scroll down the page and click on "Email Accounts" in the "Quick Shortcuts" section.

On the "Email Accounts" tab, click the "Password and Authentication" link for the email account you would like to change the password for.  Enter your new password in both fields and click the "Change Password" button.