Well guys there are no exact way to change the yahoo email address. The yahoo doesn’t provide any kind of option in the setting which modifies the yahoo email address. Make sure there in no straight solution regarding to your problem but there is some of the indirect path which you can use to change the email address.
Suppose if any of the user forget their password of their yahoo mail account and now he want to change their email address so the one and only solution is to create a new account. But make sure you can change your from name in yahoo mail. For this:
1) First go to yahoo mail through your email address and password.
2) Now go to setting icon and click on setting.
3) After that move to account section and click on edit button
4) Here you can enter your new name in the sending name box and finally click on save button.