Username

Not only here, you can't change your user name in any website in internet, because it is the main for a account. you must remembered your id in every website. and the solution is you can select o fancy user name and maintain this user name to all websites. for your req you must create your new id. you can't change or edit your user Id.

you can not change you user name because its the name you have created while yu created your login on this site now to have different logging name you will have to create new account on the site