I need to know how to defrost the refrigerator and I don't have the user manual. I've ready other people's comments on this fridge and I think they are saying that you push in the red button on the knob that controls the amount of cold in the fridge. But I don't know what happens after that.Does the button pop out by itself? Does the button shut off the entire fridge and therefore the freezer defrosts? how long does it take to defrost? Help...