Upgrade iPhone 3GS to iOS 6.1.6

WARNING: Before perform the update, always perform phone backup! The author will NOT be held responsibility under any circumstances.

PRE-CHECK LIST

1. Make sure the phone battery is fully charged or connect to direct power source (recommended).

2. 'Wi-Fi' is connected to download the iOS 6 package.

3. Full iPhone 3GS backup using iTunes. Follow this guide to install iTunes; http://emanduel.blogspot.com/2012/07/install-itunes-on-windows-xp-pro-sp3.html.

4. Once backup completed, disconnect the phone.

UPDATE!

1. On iPhone 3GS, To view installed version:

   Settings > General > About. Look for Version: 5.1.1

2. Settings > General > Software Update

3. Install Now > Agree

4. The device will reboot and upgrade on progress.

5. Once finish, it'll reboot. Swipe to continue.

6. Update Completed: Continue

7. Location Services: Disable Location Services. Next > OK

8. Apple ID Sign ID: . Next > Agree > Agree

9. Messaging: Check only 'Your Phone Number'. Next

10. Thank you: Start Using iPhone