To change your email address:
Log in to Twitter.com and go to your settings page.
Under Account settings, type your new email address into the Email field. Note: An email address can only be associated with one Twitter account at a time.
Click Save at the bottom of the page.
A dialog box will appear asking you to confirm your Twitter password. Enter your password in the box and click Save changes.
You'll see a yellow reminder message on your homepage asking you to confirm your email change. It will stay there until you confirm your new email address (see steps to confirm below).