You might be able to change it yourself. Up near the top of the page look for >user cp. Click on that and then Edit Profile. On that page about half way down and right below "Birthdate:" you will see "Custom User Text:". On the right side, type in what you want under your user name and at the bottom of the page, click on Submit Modifications.
See if that will work for you. If not, then one of the moderators will have to do it for you.