Step 1: Download redsn0w 0.9.4 using our Jailbreak Programs Tools
Step 2: Download your firmware using our iOS versions Tools
Step 3: Open redsn0w and load the downloaded firmware from step 2
Step 4: Push next and check desired options. I do recommend only install Cydia.
Step 5: If redsn0w asks you to put your device in DFU mode, do this.
You will now have a jailbreak device.