Replace a stove burner knob by pulling the existing knob from its shaft on the stove and installing the correct replacement knob onto the shaft by lining up the hole in the knob to the shaft and gently pushing. Make sure the replacement knob works with your specific stove. If a replacement knob is not available, purchase and install an adapter between a universal knob and the shaft.
Most stoves use the same burner knob construction: a tightly fitted knob held in place by friction on a D-shaped shaft. The D-shape affords the knob only installation position, which prevents the knob from misrepresenting the stove's heating temperature.
Before replacing any knobs, make sure the oven or stove is switched off and cool. Manually remove any grease or debris from shaft if needed. Use pliers to remove a knob that is particularly stubborn. SFGate.com recommends leaving any intact seals under the knob in place. Before replacing the knob, clean the shaft with a damp cloth or a non-lubricating cleanser.
Many burner knobs are made from plastic and break over time or when significant pressure is applied. If this occurs, replace the knobs quickly as the knob may display inaccurate information, such as reading that a burner is off when it is actually slightly on.