To change your user profile name, you only need to visit your user settings page as directed in these instructions and as show on the image to the right. Once the page loads, you will notice that you are automatically taken to the "(BASE) Profile Settings Page", where you can change your user profile name to your heart's content.
As with the two images provided below, you will notice that there's only one input available, your user profile name. Make your changes here, and safe them by selecting the "Save Changes" button underneath.
Once your name change has been completed, you can go back to your profile page by selecting the profile icon to the left hand-side of the page. It is the yellow person icon/button just directly above your base user profile settings.