Microsoft Xbox Primary Email/Alias Won't Change

You have to put one e-mail as primary, and delete the another to make the changes.

For this you can contact support and they can help you. (800) 469-9269 if you're in the US/Canada or
http://support.xbox.com/contact-us

Hello AlanMacielBR,

Thank you for posting on the Xbox forums. We understand that you are interested in learning how you can move an Xbox profile from one Microsoft account to another. At the moment, this feature is not available for Microsoft account. The only option is
to change the primary email address(primary alias) of the Microsoft account that has your Xbox profile. The account owner must

change the primary alias of the account that has your Xbox profile to the intended email address. The account owner can then use the previous email address by adding it as a primary alias to a different Microsoft account. However, If you remove an alias
that's an email address from a Microsoft domain (like @hotmail.com, @live.com, @outlook.com, or @msn.com), you're permanently deleting the alias and it can't be associated with any Microsoft account again. We hope this information helps AlanMacielBR!

Hello Daniel Burke_92,

Thank you for posting on the Xbox forums. We need a little more information to ensure that we provide the correct solution. Are you wanting to use the email address from the older Microsoft account and place it on your current account? Do you
mean that you want to move an Xbox profile from one Microsoft account to another? It is not possible to transfer an Xbox profile's content, currency and saved data from one account to another. You can change the primary alias of an account.

The primary alias is the email address that is used to sign in to the account. Keep in mind, you cannot have the same primary alias on two different Microsoft account. You would have to

change the primary alias on the old account, remove the email address that you want from the old account, add the email address that you want to your current account and make the email address that you want the primary alias on your current account. If
you take these steps, your relative's primary email address will change on his or her account. If your relative uses applications on other devices to access his or her Microsoft account, he or she will need to update those devices with the new information.

Warning:

• If you remove an alias that's an email address from a Microsoft domain (like @hotmail.com, @live.com, @outlook.com, or @msn.com), you're permanently deleting the alias and it can't be associated with any Microsoft account again.
  
  Make sure you save any info that you want from this alias before you remove it. All your email and contacts for this alias will be immediately deleted from the server and can't be recovered, and you won't be able to access Microsoft
  services like Xbox, Skype, and OneDrive if they use that alias.
• If you're removing a primary alias, you'll need to choose another primary alias before it can be removed. If you’re using the primary alias to sign in to Microsoft services, you may not be able to sign in to these services after you delete
  the alias.
• If you remove an email address from a non-Microsoft domain (like @gmail.com), then it usually becomes immediately available to be added as an alias on another Microsoft account.

Yes you can change the original email address. This process is called changing the primary alias. The primary alias is the email address that is used to sign in to the account. The article explains how to complete this process.