Yes I Can!

How to Jailbreak iPhone 3GS on iOS 4.0.2 with PwnageTool
LinkShare Referral Program

LinkShare Referral Program
Follow the instructions below to jailbreak iPhone 3GS (old bootrom) on iOS 4.0.2 with PwnageTool.

Step 1: Download and install the latest version of iTunes.

Step 2: Now start iTunes and sync your iPhone with your PC or Mac so that it backs-up all your important data including settings, apps, music, contacts and photos.

Step 3: Download PwnageTool and the original iOS 4.0.2 for your version of iPhone . Move all these files to your desktop.

Step 4: Start PwnageTool and select your device:

Step 5: PwnageTool will now automatically detect the correct firmware for your device as shown in the screenshot below:

Step 6: Click on “No” when PwnageTool asks you “Do you have an iPhone contract that would activate normally through iTunes?”:

Clicking on “Yes” will update your baseband to the latest version. Click on “Yes” only if you are on an officially supported carrier like AT&T.

Step 7: PwnageTool will now create the custom .ipsw file for your iPhone which will be jailbroken.

The following “ihaz Success” screen will confirm that the requested .ipsw file has been created successfully.

Step 8: Once the .ipsw file has been created, you will now have to restore your iPhone to this custom firmware 4.0.2 that you just cooked using PwnageTool for your iPhone. Click on your phone icon from the sidebar in iTunes. Now press and hold left “alt” button (“Shift” button on Windows) on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release the “Shift” button.

This will make iTunes prompt you to select the location for your custom firmware 4.0.2 file. Select the required custom .ipsw file and click on “Open”.

Step 9: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and don’t do anything silly. Just wait while iTunes installs the new firmware 4.0.2 on your iPhone. Your iPhone screen at this point will be showing a progress bar indicating installation progress. After the installation is done, iPhone will restart automatically and you should now have a fully jailbroken iPhone running on iOS 4.0.2.

Step 10: Once you are done with the unlocking and jailbreak process. You can now restore all your settings, apps, music, contacts and photos to the newly installed firmware version 4.0.2 by restoring the backup that you made in Step 2 from iTunes.

http://www.redmondpie.com/