Tpday, I already posted a guide to Jailbreak iPhone 3G and iPod Touch 2G on iOS 4.0.1 using Redsn0w then Unlock using Ultrasn0w 0.93 for Both Windows and Mac Users, But A lot of people asked me about iPhone 3GS (Old Boot), I didn’t leave them back.. I already found a way using PwnageTool which has been achieved by Criminal 90 ToolJail Author, So Let’s begin the Jailbreak..
I think that there’s no need to post a guide because it’s already posted, It’s the same steps as Jailbreaking iPhone 3GS on iOS 4, Just navigate PwnageTool to iOS 4.0.1 and customize it as you want then upgrade using the Custom Firmware, All What you have to do is to download the PwnageTool (links at the end) and iOS 4.0.1 FW, then follow the steps posted here.
After Done with the Jailbreak, You can unlock using Ultrasn0w 0.93 by following the step by step guide posted here, MUST Be Jailbroken
Download PwnageTool achieved by Criminal 90
Download iOS 4.0.1 Firmwares
Download iTunes 9.2