1. How to get the gamer's code: A gamer's code will be created when you log in to the Xbox application for the first time. On the Start symbol of the computer's Start screen, swipe to the "All Applications" list, and then select Xbox.
2. How to change your gamertag online through a Web browser:
Before you start, please make sure you have a Microsoft account. If not, you need to create one. Then, visit the official Xbox social networking site online. Log in to your Microsoft account, and if you already have an Xbox gamertag, you will see it in the upper right corner of the screen.
then you will see a text box where you can enter the desired Xbox player code. Press "Check Availability" to see if the gamertag is available.
if you receive an error message: "the name is not available. Try a different username ",and then you need to consider other usernames and do it again. Otherwise, you will go to the next menu, where it will show you a preview of the new gamecodes across different Xbox services.
the first modification of the player's code is free, and the second modification fee is ten dollars.