How do you change your username on you tube?
Unfortunately, it's not possible to change your YouTube username display. You can only change the "name" box in your profile settings. You may, however, sign up for a new YouTube account with the username that you desire.
You cant change it, unless you make a new youtube account. sorry :(
You can change the name that is displayed on your channel. Or you need to delete your whole YouTube channel and create a new one through Settings.
You can't, it says on the side, Warning: Once you choose this username, you will not be able to change it