[How-to] Disable OTA updates on Stock + Rooted ROMs
1. Download FOTAKill.apk* and copy to your Phone/SD
2. Use a root explorer (such as ES Explorer) to copy the file to /system/app
3. If the update already downloaded, use your root explorer to delete it from /cache
If the update notice is still in the notification bar after the reboot, simply swipe it away. That should be the last time you are ever prompted to update via OTA. Even if you manually go to system update and click check now it will no longer offer you the OTA. You can simply delete the apk from /system/app to reverse this mod.