We don't have access to be able to change your name, you have to do that yourself.
You do that via your Adobe ID.
Click on “Welcome, Your Name” at the top right side of the page (under the Adobe search field)
Select My Account Sign in with your current Adobe ID (you should now be on the Your Account page) Scroll down to the Account Information section Click on Edit Your Account Information Look for the "Scren Name" field on that form and change your name there.
Click on Update & Continue at the bottom of that page.
The next time you sign into the Forums they should pick up this change from your Adobe ID account.