By clicking on your name at the top-right and then clicking on "My Account", you will then be redirected to your account settings.
At the bottom of the page within the "My Profile" tab, click the "Edit" link, you will then be redirected to your Account Information page. Next to the "Email" field, you will find a link that says "Change my email to login". Click this link and enter your desired new login email and select "Save".