For what reason can't you speak to a Yahoo representative to access the account? from sam wilson's blog
With the assistance of the Yahoo emailing platform, you are qualified to
create more than one account. Notwithstanding, make sure you have to pick an
assorted username to create an account and you can also access basically each
account accordingly. To use another, you have to switch it. You can easily
access your old account by placing the correct details. In addition, speak to a Yahoo representative.
The Wall