Step 1)
Go to click the Download link.

Step 2)
Save the downloaded file.

Step 3)
Double click the limera1n.exe file to launch the application

Step 4)
Click the big make it ra1n button and follow onscreen information

Step 5)
When done, power on your iPhone you will see a new icon on the SpringBoard – limera1n. Press it to continue

Step 6)
When limera1n opens select Cydia then press the Install button.

Step 7)
After the Cydia installation has completed reboot your iPhone.

Step 8)
After your iPhone restarted run Cydia and allow all updates.