http://www.evasionjailbreak.com/
+ ovo
You will Need The latest Version of Redsn0w, ios 6.0 IPSW file, and a device with an unaltered version of 6.1.3 installed.
1. Download Redsn0w from the link Below, extract and open it
Redsn0w:
Windows -
http://bit.ly/Txjd9N
Mac -
http://bit.ly/Txjcm4
iOS 6.0 Firmware File:
http://bit.ly/vJezxl
NOTE: If you're on Windows Vista/7/8 then you should right click Redsn0w and set compatibility to windows XP (service pack 2) and then run it as the administrator
2. Go to Extras and click Select IPSW. Then select your iOS 6.0 (not 6.1.3) firmware file.
3. Go back and click "Jailbreak" and enter DFU mode by following the below steps or follow the on screen guide in redsn0w:
a. Make sure your device is plugged in and turned off then hold down the power button for 3 seconds
b. Continue holding the power button and start holding the home button for 10 seconds
c. Let go of power and continue holding home button for 15 seconds
4. Select install Cydia and any other options you want except "Install custom bundles".
5. Wait for it to finish and reboot
6. Close out of Redsn0w
7. Open Redsn0w and go to "Extras"
8. Click Select IPSW file again and select the iOS 6.0 (not 6.1.3) firmware file.
9. Click "Just boot" and enter DFU mode again by following the instructions in step 3
10. You will now have a tethered iOS 6.1.3 jailbreak.
11. If you want the semi untethered jailbreak you will need to add the repo:
http://thebigboss.org/semitether/
12. Once that source is added look for the package named "SemiTether" and install it.
13. Once it's done it will ask you to respring your device.
14. You now be able to boot up without redsn0w! You will however have limited functionality. Cydia and safari won't work and nor will any packages you downloaded from cydia until you boot with redsn0w by following step 7 onwards
http://www.iclarified.com/29764/how-to-jailbreak-your-iphone-4-using-redsn0w-windows-613
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