To delete or change a mobile device:
- Click the "Messenger" menu in Yahoo! Messenger and select "Preferences."
- Click the "General" category.
- Click the "Edit mobile device" button and enter your Yahoo! ID and password to sign in to Yahoo! Mobile.
- Under the Other Mobile Devices section, click the trashcan icon to the right of the device.
- Click the "Delete" button.
Note: To change your Go Mobile device, you must first delete your original device and then register your new device.