This article only applies to Mojang accounts. For older Minecraft accounts that have not been migrated (in which you log in with your username),
see this article for legacy Minecraft accounts.
To change the email address on a Mojang account, visit account.mojang.com/me/settings. You can either have instructions sent to your current address or if you don't have access to that email account, you can have it changed by passing a security challenge.
If you have registered for a Mojang account using the incorrect email address, and have not made a purchase, you can re-register under the correct address.
If you have lost access to your Mojang account email address, we recommend contacting your email provider in order to regain access to the email account. This way, you can edit any settings associated with your Mojang account (including the Mojang account email address).
If you are unable to change your Mojang account email, have your transaction ID or gift code available and contact Minecraft support.