Now it’s possible to jailbreak iPhone 3G S, thanks to the iPhone Dev team for their much awaited solution to
3GS OS 3.0 with RedSn0w. However to install their UltraSn0w application to unlock iPhone 3G S, you need to first jailbreak iPhone 3GS. So here is a step-by-step guide to
jailbreak iPhone 3G S usin using RedSn0w for Windows and Mac users. For unlocking your iPhone 3GS first jailbreak with following guide after a successful jailbreak follow our guide on Unlocking iPhone 3GS with UltraSn0w.
Step 1: Connect your iPhone to the computer and launch RedSn0w from unzipped folder. In the Window click on the browse button to navigate to the folder where your firmware is downloaded and select the 3.0 firmware ipsw. In next Dailogue check mark the Install Cydia option to Jailbreak your iPhone
Step 2: Now turn off your iPhone but make sure it is still plugged in to USB port. The next step is to put your iPhone in DFU mode, Hold the Power button for 5 seconds, Hold the Home and Power buttons for 10 seconds, then release the Power button and continuing holding the Home button until your iPhone is in DFU mode.
Step 3: That’s it after 5 to 10 minutes of process you will get your hands on a Jailbreaked iPhone
After this, proceed to Unlock, Activate via Ultrasn0w method.
Step 4: After unlocking with Ultrasn0w on 3GS reset your network setting once from Settings->General->Reset->Reset Network settings once. The process is very similar as iPhone 2G and 3G jailbreaking.