1.) Cut the bar into 4 peices
2.) Wash your car
3.) Wet your car with Quick Detailer or soapy water and rub the clay in a front to back motion, if your using the QD, buff the area dry, if your using the car soap just leave the area alone until your done where you will wash the car again.
As the clay becomes dirty, fold it over for a cleaner side.
Not much too it, if your car is bad and if you rub the clay over the wet paint you hear a slight rough sound and as you rub more and more you'll hear it go away.
Feel your paint when it's dry, clay an area, dry it and then feel it again, it'll be nice.