Basically, I followed these steps (you might want to do it while using the stock rom, to ensure you have the activate app):
1. Turn the phone on.
2. Dial ##847446#.
3. Now, you are on the programming menu.
4. You will see: 1)Activate Phone, 2)View, 3)Edit and 4)Done.
5. Select Edit.
6. You will now see MDN and you may see your phone number at the bottom.
7. Delete your number and enter the number 1 ten times. Press ok.
8. You should see now MSID and some numbers at the bottom. Delete them
all.
9. And now enter the number 1 ten times again. Press Ok.
10. You will be back on the programming menu.
11. Scroll down and Select "Done". The phone will turn off and on by
itself.
Once the phone is back on, repeat the same process, but this time just chose
Active Phone.
Hth,
BOb