To change your username and/or password, log into your account and clicking the “Account Info” tab. Change your username by typing in a different one and click on the “Update” button. The changes will take effect immediately.
The same can be done for changing your password. Simply insert a new password and re-type your password for confirmation and then click on the “update” button. Your password will be changed immediately.
Alternatively, you can reset your password here.