xbox transfering information

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today Ben

I don't like to give bad news but unfortunately any kind of content transfer between Microsoft accounts can't be made
This is for security reasons

An Xbox account is basically a Microsoft account. If an email address associated with that account was being closed down, you can just an another email address as an alias to that account and still get access. You don't need to set-up another account.

https://support.microsoft.com/en-us/help/12407/microsoft-account-change-email-phone-number

It's not possible to transfer data (i.e. purchased games or subscriptions) from one account to another.

Nothing can be transferred between accounts.

Hello!

If there's nothing else tied to your (his) Microsoft/Xbox account your best option would be to change the e-mail address and all the information on the account to him and make the existing account his. Then if you needed to, create yourself a new account.
Otherwise the only option would be to create him a new account in which it would be a new account without any of the content earned or purchased on it.

Hi there TeroneHodge

There isn't a way to transfer game data or achievements from one account to another. But the xbox live might be shared on the xbox one if you are both on the same console set as home.