Deleting Your Minecraft Account
Log into your Mojang account and request deletion. From there, log in and access your ‘Settings’ tab. At the bottom, there should be a ‘Request Deletion’ button. Click the button, and you’ll be asked to verify some of your information. In the majority of cases, your account should now be eliminated.
Once you are on the new Mojang accounts, go to account.mojang.com and sign in. Under “My Account” click “View account settings”. Once you are at the settings page, click “Learn how” under “Delete Account”, and then click “Request Account Deletion”.