Account not set up

if your email address is a Microsoft email (@hotmail, @live, @outlook) then you wont be able to remove your account from the Xbox account.

removing Microsoft email accounts from Xbox accounts permanently deletes the email account and you will no longer be able to access it

all you can do is add an alias email address then promote that to be the main email address.

You can't move or transfer from one account to another, all you can do is change the email account associated with that profile.

If your son doesn't have a lot of game progress or purchases on that (your email) account, I highly recommend to just create a new account for your son.

As AridLizard already said, if your Email is already a Microsoft Account (by using a Hotmail.com, Live.com, Outlook.com address), or if you already use other services on your account like OneDrive, Office etc., then you won't be able to use these services
with your account anymore, if you move the account over to a new Email.

Also, in order to move the Account to the Email of your son, the email MUST NOT be a Microsoft Account already.

If all those points are met (you don't have important stuff on your account, and your son's account is not yet a Microsoft Account), you can simply sign into your account at
https://account.microsoft.com and add your son's email as a sign in alias.

Then you make your son's email the primary sign in alias, and remove your own email.

here is how you can change the email https://support.xbox.com/en-US/my-account/microsoft-account/change-email-sign-in-for-microsoft-account

Hello CrippledCripler,

We see that you are a registered Rewards member. There is not a confirmation e-mail for registration. You can confirm your registration by viewing your MyRewards page, which will show you your current Rewards details, and not prompt you to join the program.
We see you have been registered since the 25th of July.