[If you are able to sign in to your Nintendo Account]
You can change your Nintendo Account email address from the following page:
To change your email address, a verification code will be sent to the email address associated with your Nintendo Account.
* If a sign-in screen appears on the redirected page, please sign in to continue.
[If you can no longer access the email address registered to your Nintendo Account]
Please contact the Nintendo Support office for the country or region set in your Nintendo Account using the website below.