Facebook has added a great new feature which allows you to change your username or Facebook E-Mail address. You can even change the username of your Facebook page.
Note: You can only change your username once if you have not exercised this option yet.
How To Change Facebook Username:
1) Go To Account Settings in the right-hand corner of your Facebook page and choose General Account Settings.
2) Click on edit on the same line of username.
3) Now enter your new preferred username. If it is available, save the changes.
Update: Facebook recently also made some unwanted changes to users’ individual profile pages. Many users complained that Facebook has changed their personal email address which is being displayed on an individual user’s profile pages and replaced it with a @facebook.com address.
To change it back to your personal Email address, Go to About section of your Facebook Profile. Click Edit where your Contact Info is displayed. Click on the circle along with your Email Addresses. And change the setting from “Hidden From Timeline’ to “Shown on Timeline” and save the changes.