To jailbreak these devices you need RedSn0w app that you need to download from developer’s official website
Requirements
Compatible devices: all generations of iPhone, iPod Touch, iPad
Untethered jailbreak: iOS 3.0—5.1.1 (all devices)
Untethered jailbreak: iOS 6.0, 6.0.1, 6.1 beta (iPhone 3Gs old bootrom only)
Semi-tethered jailbreak: iOS 6.0, 6.0.1, 6.1 beta (iPhone 3Gs new bootrom, iPhone 4, iPod Touch 3 and 4 generation only)
Preparing
1. Connect your device to your computer using USB
2. It’s recommended to jailbreak devices with clean firmware. This will make jailbreak faster and will prevent errors.
2.1. First of all backup in iTunes (right click on your device in the right column in iTunes > Back up).
2.2. If the firmware wasn’t just installed you need to reset your settings to make jailbreak faster (Settings > General > Reset > Reset All Settings). After jailbreak you can restore everything with your iTunes back up.
3. Close iTunes.
4. Exit all antiviruses and firewalls.
5.Download - the latest version of RedSn0w from developer’s website.
6. Run RedSn0w. On Windows it’s recommended to run as administrator in Windows XP sp3 compatibility mode (right click on redsn0w.exe > Properties > Run this program in compatibility for:).
Guide:
1.Click Extras > Select IPSW. For now redsn0w can’t read iOS 6.0 and 6.0.1 .ipsw files, but jailbreak for these firmware versions is semi-tethered. Jailbreak iOS 6.0-6.0.1 on A4 devices without selecting the path to the firmware file and go straight to step 5.
2. Indicate the path to the .ipsw file with same official firmware you have on your device. Click Open. If you’ve already downloaded firmware from iTunes, the .ipsw file is in Software Updates folder in:
Windows ХР: C:\Documents and Settings\user_account\Application Data\Apple Computer\iTunes\
Windows Vista, 7: C:\users\user_account\AppData\Roaming\Apple Computer\iTunes\
Mac OSX ENG: \Users\user_account\Library\iTunes\
Instead of user_account use your account.
3. After the identification is complete click Next.
4. Click Back to go to the main screen of the program.
5. Click Jailbreak.
6. You can see the screen where you can choose your options. For jailbreak you need to mark Install Cydia. Other options you can mark on as needed.
7. When you marked on everything you wanted click Next.
8. Now you need to enter DFU mode. It bypasses the operating system of your device and replaces firmware directly. OS doesn’t even start the download, everything that can possibly be disabled is disabled, USB transfers exclusively technical information. You can do that at once or you can click Next and follow the interactive guide:
As soon as the first line becomes active (black), press Power button (Off button at the top) and hold it for about 3 seconds.
As soon as the second line becomes active (black), hold the second button, Home (the round button at the bottom center). Now you’re holding 2 buttons. Do that for about 10 seconds.
As soon as the third line becomes active (black) release Power button (Off button at the top), but keep holding Home (the round button at the bottom center) until the jailbreaking starts. It’s about 15 seconds.
If it didn’t work from the first time click Back and try again.
After that your device is in DFU mode and display goes black while jailbreaking is happening on your PC.
9. Wait for the installation to be complete and don’t do anything with your device until Spring Board loads up. After that click Back and go to the main screen of the program.
10. Select Extras > Just boot.
11. Click Next and enter DFU mode again like in step 8.
12. Wait for the device to reboot.
13. The main jailbreak procedure is done. Now to make Cydia run correctly turn on Wi-Fi or 3G, open Cydia, and give it a few minutes to update system files.
14. You’re done. Your device is jailbroken.
Rebooting a device with tethered jailbreak
If after you reboot your device it’s stuck on apple logo endlessly rebooting don’t panic, you have tethered jailbreak on your device. To reboot your device or turn it on after rebooting do the Preparing and steps 10-12 of the Guide above.
If after rebooting your device works, can make and receive calls, runs paid apps, but Cydia, Safari, and previously installed cracked apps don’t work you have semi-tethered jailbreak. To make your device fully functional again do the Preparing and steps 10-12 of the Guide above.
Additional features (Extras)
Options in Extras menu:
Just boot – boot the device with tethered jailbreak.
DFU Pwned – enter special Pwned DFU mode to install custom firmware.
Recovery fix – exit Recovery Mode when there are errors like 1015 error while installing earlier version in iTunes.
SHSH blobs – save, check, and use SHSH certificates.
Fetch – save and send SHSH certificated to Cydia. Saves the certificate to your PC, then searches it in Cydia, and sends it to Cydia server if there’s no matches.
Verify – verifies SHSH certificates. The app searches in Redsn0w, TinyUmbrella and Cydia, you can also verify several SHSH certificates at once.
Submit – send SHSH certificated to Cydia server. You can copy all TinyUmbrella cache and send it to Cydia servers.
Query – show all the saved SHSH certificated available for your device in Cydia.
Stitch – personalize firmware if there are SHSH certificates.
Select IPSW – manually select the firmware file.
Custom IPSW – create custom firmware without upgrading baseband.
Even more – more additional options.
Restore – downgrade with Redsn0w.
Preferences – presets (extended settings).
ECIDs – ECID of all the devices used by Redsn0w in hexadecimal or decimal system.
Boot args – set test booting.
Boot logo – set animated booting logo.
Clear cache – reset all the settings and remove all the content.