I am not Zen or Herb, but here you go!!
Under Profile, on the Registering tab.
You'll have to re-confirm your account after you enter your new email address.
This is the answer left in the members only section to your question by Russ.
Here are the steps
1. Click profile at the top of the page
2. Click Registration Tab
3. Enter you new email address
4. Enter you new email address again to confirm it
Click submit to save the changes