The first step is to go to yahoo page and then go to email login from there itself. Log into the mail account for which you wish to change the password. Once you are logged in then you are required to tap on your name from the upper left corner of the window and thereafter tap on Yahoo account info. You will have to enter the email and password again and then you will have to select "Manage passwords and account security" option which will take you to the online account management page. You will now re-enter the account credentials and that will direct you to password change page. Enter and confirm your new password. Once you click on the "Submit" option you are all done.