Before you start, First things first Make sure to have the latest itunes Installed on your computer and firmware 4.2.1 on your iOS device

This is a step-by-step tutorial to teach you how to jailbreak your iOS Device (iphone 3g, 3gs, 4, Ipod touch, and ipad) running firmware 4.2.1 please make sure you fully understand before continuing as it may VOID your warranty, Pixalies is not responsible for any damages that following this tutorial may cause. but if you know what you doing please continue and after you finish dont forget to give a donation for this project

Here we go….

1) Go to Greenpois0n website and dowload the latest version for your platform (Mac, Windows or Linux), After you download double click on the “apple skull Greenpois0n logo”

2. Make sure your iPhone / iPod Touch / iPad is attached to the Mac and click ‘Jailbreak’.

NOTE: This will NOT unlock your iPhone (enabling it to be used with other carriers).

3. Greenpois0n will now give you 5 seconds to get ready. It will now ask you to ‘Press and hold the sleep button.’ for 3 seconds and then ‘Continue holding sleep; press and hold home.’ for 10 seconds. After this, it will finally tell you to ‘Release sleep button; continue holding home.’ for another 10 seconds.

4. Now, it begins ‘jaibreaking’ the device and a few seconds later, greenpois0n displays success message, click ‘Complete!’ to quit the application. Some code will scroll on the screen of your device and it will then reboot.

5. When the device reboots, make sure you have an active internet connection on it.

6. Navigate to the last page of the device’s springboard and open the Loader app.

NOTE: The application icon might appear blank but there’s nothing to worry.

7. Now select Cydia and tap on ‘Install Cydia’ button that pops up. It will now download Cydia. Once done, it will ask if you want to remove the loader app, you can choose ‘Remove’, if you want to and then the device will re-spring (refresh).

8. After the device re-springs, you will have Cydia installed.

Congratulations!

Your iOS device is now successfully jailbroken.

UPDATE: Greenpois0n RC5 “Failed” Error (MAC)

1. Make sure you’re using Greenpois0n RC5_2
2. Make sure device is connected to your Mac
3. Open Terminal
4. Type “cd Desktop” without quotes and hit enter
5. Type “open Greenpois0n.app/Contents/MacOS/greenpois0n” without quotes and hit enter. A second Terminal window will open and Greenpois0n will start
6. Follow the instructions in Greenpois0n to enter DFU mode and it will jailbreak
7. Once jailbroken, a green “Loader” will be added to your device. This is supposed to allow you to install Cydia, but mine would not. If yours is the same, go to step 8
8. Turn off your device
9. Open Redsn0w 0.9.7b6
10. Make sure the only option checked is “Install Cydia”
11. Follow the instructions in Redsnow
12. Voila! Cydia is installed, and you have an untethered 4.2.1 jailbroken device!