- Hold down the Sleep/Wake and Home buttons at the same time. When the Apple logo displays, do not let go of the buttons. Hold both buttons down until the recovery mode screen appears.
- When the option to Restore or Update appears, choose Update.
- Allow iTunes to try to restore iOS without wiping your data. iTunes should start downloading applications for your device. Allow the download to finish if it takes more than 15 minutes and your iPhone exits recovery mode, then repeat these procedures.
Set up your device when the Update or Restore has been completed.