after you finish to update!
1. jailbreak and downgrade ipad baseband if your baseband is 6.15
2. just boot!
3. unlock no wifi..
4. restart 2x..
5. go again to redsnow and just boot!
6. wait for signal..if no service
7. go to cydia/manage/source/ click repo666.ultras0w.com
8. click ultra snow and modify!
after you modify wait for the signal and smile!
just untheterd your phone