This instruction will guide you to Jailbreak your iPhone 4 or iPhone 3GS on iOS 5.0 and keeping your lower Baseband so you could Unlock your iPhone. Its a complete guide with screenshots.
This is so far the only process to safely update your iPhone 3GS or 4 in 5.0 without updating baseband, and jailbreak it. Then you could unlock using UltraSn0w or Gevey SIM card. Please note this jailbreak is tethered for every device but the old bootrom iPhone 3GS which means you will need to connect your device to the computer each time you reboot. Also, it may be prudent to save your SHSH Blobs by following this tutorial before continuing if you haven’t already.
Create a folder on your desktop called Pwnage
Download RedSn0w 0.9.9b5 from here and place it in the Pwnage folder. Likewise, download the 5.0 firmware from here and place it in the Pwnage folder.
Extract the RedSn0w zip file by double clicking it.
Launch the redsn0w application from the redsn0w folder we just extracted.
Click to select Extras from the main menu.
Click to select Custom IPSW from the Extras menu.
Navigate to the Pwnage folder on your desktop and select the iOS 5 IPSW we downloaded then click Open.
RedSn0w will now begin building a custom IPSW for you.
You’ll be notified once RedSn0w has completed building your IPSW. Click the OK button.
Click the Pwned DFU button from the Extras menu.
Plug your iPhone into the computer and make sure its OFF then click the Next button
RedSn0w will now guide you through the steps to get into DFU mode.
Hold down both the Home button and the Power button for 10 seconds.
Release the Power button and continue holding the Home button until RedSn0w detects the device.
RedSn0w will run the LimeRa1n exploit.
You’ll then be notified that your iPhone is in Pwned DFU mode.
Launch iTunes by clicking its icon in your dock.
Select your device from the list on the left then under the Summary tab hold down the Option key and click the Restore button.
You will then be asked to select your IPSW for restore. Navigate to the Pwnage folder on your desktop and select the IPSW that begins with NO_BB then click the Open button.
iTunes will now restore and jailbreak your device using the Custom IPSW.
Once you have jailbroken you will need to rerun redsn0w to boot tethered.
From the main RedSn0w menu click the Extras button.
Select Just boot from the Extras menu to just boot tethered.
After the Jailbreak, use UltraSn0w to unlock from here or get the Gevey SIM for iPhone 4 to unlock from here
All credit goes to iClarified, Thanks Guys for putting everything together. Also @MuscleNerd & his iPhone Dev Team for making Jailbreak possible and hard work.
You can also press the left/right arrow key on your keyboard to go to previous/next post