If you are wanting to change the email address that Billing Receipts and Notifications go to, see your Settings Page to change that

However to update your email address via the User Profile page there are a few steps required.

Step 1. Add the new email address to your user

Step 2. Set the new email address as your primary email address

**Please note, this means your login username will change to be this email address from now on**

Step 3. Remove the old email address (or you can keep it attached to your account as a secondary email if you'll still be using it occasionally)