How do I change the existing mobile number on file with my email address, to recieve yahoo alerts to my new #?

I recently tried to sign-up to yahoo! sports alerts but my previous mobile number was in step 3 in the sign-up process and not allowing me to edit/change/add my new current mobile number to update the database so I can recieve alerts. Help!
How do I change the existing mobile number on file with my email address, to recieve yahoo alerts to my new #?
1. Go to the My Mobile page at:


http://sites.mobile.yahoo.com/wireless/m...


2. Click the Add Alerts Device.


3. Choose the Device Type and Daily Message Limit.


4. Click Continue to Step 2.


5. Enter the device's email address, or enter the device's phone number and choose a carrier name and phone manufacturer.


6. Click Continue to Step 3.


7. Choose a model or My phone is not listed.


8. Click Continue to Step 4.


9. A confirmation code will be sent to your device. Enter the five-digit confirmation code.


10. Click Confirm.