^ Indeed, you can't.

Username changes are disabled on UG because the process is a strain on the website servers. We only occasionally allow it for privacy reasons (e.g. a user who used his real name as his username and wants it gone), but other than that we don't normally allow usernames to be changed, I'm afraid.
In THAT case. This is my real name...I no longer want it as a username.


Yes, poop.