If you're already logged in to the site, you can change your address under "My Profile" on the top right of any page.
If we have your email correctly, we should have sent login information to it. That email should also work in the "Request new password" feature. If it doesn't, please send an email to email@example.com with "Request new password" in the subject line. This requires human review so may take part of a business day.
Or just send your old and new addresses to firstname.lastname@example.org.
Or call us at 1-800-989-8274 or 1-301-656-8274.