[How to] jailbreak iPhone 4 on iOS 4.2.1 using PwnageTool for iPhone 4, 3GS on 4.2.1 and Unlock with Ultrasn0w guide

PwnageTool Bundle is one of the most used bundle found once there is some new firmware upgrades and jailbreaks found and this time there is a hacker named Nadeem Ateyeh who has now released a bundle to jailbreak iOS 4.2.1 on iPhone 4 and iPhone 3GS with PwnageTool 4.1.3. PwnageTool which will help you to to restore to a custom firmware IPSW files with preserving the baseband so that it can be unlocked with Ultrasn0w later on which is a great thng to have if you are less trained in all of these stuffs.

so to proceed for this process to jailbreak your device with PwnageTool you need to download PwnageTool 4.1.3 for Mac and the download the latest version of iTunes 10.1.2 and have a firmware iOS 4.2.1 then simply Copy all in a folder on your desktop becasue you you need to modify the Pwnage Tool

Now simply follow the steps provided below.

How to jailbreak iphone 4 on iOS 4.2.1 using PwnageTool 4.1.3 for Mac

Steps to Modify PwnageTool

Step 1: Download PwnageTool bundle for your iPhone 4 device. Extract the .zip folder, and copy iPhone3,1_4.2.1_8C148.bundle (for iPhone 4) oriPhone2,1_4.2.1_8C148a.bundle (for iPhone 3GS) on your desktop.
Step 2: Now download PwnageTool 4.1.2 and copy it to your desktop. Right click, and then click on “Show Package Contents”
Step 3: Copy the .bundle files to PwnageTool.app/Content/Resources/FirmwareBundles/

Step 4: Copy info.plist goes inside PwnageTool.app/Content/Resources/CustomPackages/CydiaInstaller.bundle/ (IMPORTANT IF YOU WANT CYDIA IN YOUR IPSW)

How to  Jailbreak Phone 4, 3GS on iOS 4.2.1 with PwnageTool 4.1.3 with Step by step tutorial:

Step 1:goto  iTunes 10.1.2  and backup your Device.

Step 2: Open PwnageTool. Select Expert Mode  and your and click next with arrow given there

Step 3: Now Click on  “Browse for IPSW” button and then select your firmware from the folder where you have saved it.

Step 4: now here select the “General” then click the arrow button to continue.

Step 5: Now on the General settings Check “Activate the phone’ and if you are not with an official carrier and click the arrow button to continue. If on official carrier uncheck “Activate the iphone” option and continue.

Step 6: Now double click on OpenSSH under Select Packages tab.

Step 7: Select Packages Tab and then select OpenSSH as shown here.

Step 8: Now click on the Build button to select it then click the arrow to continue.

Step 9: PwnageTool will now create the custom .ipsw file for your iPhone and create a new custom firmware which will take  10-15 minutes for building custom firmware and then done .

Step 10: Now you need to restore your iphone with the new firmware  so   In iTunes, hold the Alt/Option key and click Restore.

Step 11: In this step now you need to select the custom IPSW that was created and click the Choose button and then Wait for a while till itunes updates the new firmware on your iPhone once completed you will be promoted once it is restart your iPhone.