Don't you like your current username anymore? You can change it to a brand new username by typing the new username under "New username" and "Confirm new username". Once you have clicked on "Save", it will be immediately shown under "Your current username".
Did you forget your username?
Did you forget your username? Quickly get it back by clicking on "Forgot your username?" on the login page. Fill in the email address you've used for your account and click on "Submit". Your username will be sent to your email address.