Here are the steps that you have to follow to delete your Yahoo account. You need to follow all the steps carefully:
Go to your Yahoo email sign up page
Or simple visit: edit.Yahoo.com/config/delete_user
Then enter emails and password
Click on next
Read terms and click on delete my account
That's the simple steps you have to follow
For more visit: https://emailspedia.com/how-to-delete-yahoo-email-account/