Dear Dumb Pecker,
Yes, you can. Go to your username and click "Contact Details", edit your email and then click "Save Changes". Once you have entered an email you will get an email from the forum asking you to verify your email account. You must click on the link in that email to regain full forum privileges. (Meaning you must use a valid email address that you have access to.)
Note: it will not say "Update your email here". It will have the email address currently on file with the forum.
Regards,
Wrye