DFU mode is so simple, you don't need to go to any site to read about it.
Press and hold the power button for 3 seconds, then while still holding the power button press and hold the home button for 10 seconds, then while still holding the home button let go of the power button. After 10 seconds of holding the home button you'll be in DFU mode. The phone will appear to be off but the screen will be black and the phone will be on.