These are instructions on how to jailbreak your iPhone 4 on 5.0.1 firmware firmware using a PC.
1. Create a folder on your desktop called Pwnage.
2. Download RedSn0w from here and place it in the Pwnage folder. Likewise, download the latest 5.0 firmware from below and place it in the same folder.
Note*
Those of you who wish to unlock please skip to “For Unlockers Only” section found at the bottom of the page.
5.0.1 (4 GSM): iPhone3,1_5.0.1_9A405_Restore.ipsw
5.0.1 (4 CDMA): iPhone3,3_5.0.1_9A405_Restore.ipsw
Extract the RedSn0w zip file by double clicking it.
Note*
The firmware restore file contained in the above download should end in an .ipsw extension. There is a known browser issue that some users may experience which causes the .ipsw file to be renamed to a .zip extension during download. If you experience this problem you will need to install the FIREFOX web browser and use it to download the file to rectify this issue.
FIREFOX can be downloaded completely free of charge from HERE.
3. Connect your iPhone to the computer and launch iTunes.
4. Select your iPhone from the list of devices on the left
5. Hold down the Option key and click the Restore button.
6. Navigate to the Pwnage folder on your desktop and select the appropriate firmware ipsw. Click the Choose button to continue.
7. Once iTunes has finished updating your iPhone to the desired firmware open the Pwnage folder on your desktop and launch the redsn0w application from the redsn0w folder we extracted earlier.
**Windows 7 users may want to try running the redsn0w executable mode as an administrator in Windows Vista compatibility. You can do this by right clicking the executable and selecting Properties from the contextual menu.
8. Once RedSn0w opens click the Jailbreak button.
9. Plug your iPhone into the computer and make sure its OFF then click the Next button.
10. RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here.
11. Hold down both the Home button and the Power button for 10 seconds.
12. Release the Power button and continue holding the Home button until RedSn0w detects the device.
13. Your iPhone will now reboot.
14. RedSn0w will now prepare the jailbreak data.
15. Select Cydia from the list of options and click Next.
16. Your iPhone will now be rebooted again and RedSn0w will begin uploading the new RAM Disk and Kernel.
17. Once this is complete you will be notified that RedSn0w is done. When your iPhone finishes rebooting (5 minutes or so) it will be jailbroken with Cydia on the SpringBoard.
BOOT TETHERED
Once you have jailbroken you will need to rerun redsn0w to boot tethered.
Step One
From the main RedSn0w menu click the Extras button.
Step Two
Select Just boot from the Extras menu to just boot tethered.
*As usual a big thanks to the iPhone Dev-Team and Geohot for their hard work and contribution to the iPhone community.
*For Unlockers Only
If you rely on a Gevey SIM or Ultrasn0w (for old basebands only) unlock, DO NOT update to the stock firmware update offered by iTunes. Instead, use this latest version of Redsn0w to cook a custom firmware file without the upgraded baseband so that you can unlock it with Ultrasn0w or Gevey SIM. To do this, click on “Extras” option and then select “Custom IPSW” option. Select the required iOS 5 IPSW firmware file, and let Redsn0w make the custom firmware for you. Once done, enter Pwned DFU mode by selecting “Pwned DFU” from Redsn0w’s Extras option, and then restore to this custom firmware using iTunes. Once done, unlock your iPhone using Gevey SIM, or follow the link below.
These are instructions on how to unlock your iPhone 4 for use with any GSM cellphone carrier. If you are on T-Mobile remember to turn off 3G before starting...
1. Press to launch Cydia Installer from your SpringBoard.
2. Press to select the Manage tab at the bottom of the screen.
3. Press to select the large Sources button.
4. If the ultrasn0w repo is not present press the Edit button at the top right of the screen. Otherwise, skip to Step Nine.
5. Press the Add button at the top left of the screen.
6. Enter http://repo666.ultrasn0w.com/ as the source url and press the Add Source button.
7. Once the source has been added press the large Return to Cydia button.
8. Press the Done button at the top right of the screen.
9. Press to select repo666.ultrasn0w.com from the list of user entered sources.
10. Press to select Ultrasn0w from the list of packages.
11. Press the Install button at the top right of the screen.
12. Press the Confirm button at the top right of the screen.
13. After installation completes successfully press the large Restart Springboard button.
14. You are now unlocked and able to use a carrier of your choice!
Enjoy your unlocked iPhone!
A5 unteathered Jailbreak (iOS 5.0 / 5.0.1) for iPhone 4S / iPad 2
Windows Version: http://cache.greenpois0n.com/dl/absinthe-win-0.2.zip
Mac Version: http://cache.greenpois0n.com/dl/absinthe-mac-0.2.zip