Changing my registered email address?

I have done multiple searches and cannot seem to find an answer to my question.

How do I change the email address attached/registered to this account?

I went to "edit my preferences" then "account."  The first entry space states "current password" and the below is says "Enter your current password to change the E-mail address or Password."  When I do this then select save, I am never given the option to change my email.  Am I doing something wrong, or can my email not be changed?

Thanks!