(1.1) To change your mobile number with Yahoo!, go to the My Mobile Web page. Look for Messenger Phone. Delete this number by clicking on the trash can.
(1.2) After clicking on the trash can, you will be taken to another page, where you must now select Delete Device.
NOTE: You will now need to go back through registration to add a new device.
(1.3) After you have deleted your previous mobile number, go back to Yahoo! Messenger on your desktop to re-register with your new number. How to set up.
Yahoo! Messenger for SMS is currently available in the following countries: See countries