I made mine when I first joined several years ago. I would like to change it now. I searched help forums, and there was another post asking how, and the response was that only email address could be changed. If this is so, please see about adding a username change capability?

I think it is not possible to change your nickname.
You can create a new account but you will lose your ranking.
You'd better send a private message to the administrator asking if it's possible to transfer your points and your belt to your new nickname.
Otherwise you will have to redo everything.