First, be sure your iPhone is on iOS 6.0 to iOS 6.1.2. in case you have important information on it, use a backup following these instructions. If you need to re-restore, firmware downloads links, which you can find here, can be useful.
Go to your desktop and create a folder. To find easier rename it as Pwnage. There you can download the EvasiOn utility. The links to download EvasiOn are here.
To download the information, double clik the EvasiOn dmg file, which you can find in the Pwnage file, so that you move to your desktop.
Move the EvasiOn app. First, go to the monted dmg and drag it to your folder you created on your desktop.
Go to the EvasiOn app icon and right click. As an anternative, you can use Control+Click. You need this to select Open from the menu for the app launching. If it is confirmed, go to the Open button once more.
Be sure you have connected your iPhone to the computer using a USB cable.
Get rid of the passcodes from your screen. After doing this, click Jailbreak button.
Download the EvasionCydia.deb file from here.
The application is recovering the information it needs from your computer to engender jailbreak data, inject stage 1 jailbreak data. Then, will reboot the device, but meanwhile wait for it to be ready for this operation. Then, inject stage 2 jailbreak data. Then, you’ll have to deal with Cydia, which will be uploaded, and after that the same thing will happen to Cydia packages list.
Be ready to unlock your device and click the new jailbreak app icon. Be careful to tap the icon once.
EvasiOn will inject the remount payload, remount the root filesystem and it will prepare the final jailbreak data. Will inject the final jailbreak data and it’s complete.
Your device restarts with Cyndia installed on SpringBoard.