Perhaps the knobs on your Frigidaire stove are looking a bit dingy and need to be cleaned, or maybe you just need to replace one that is damaged. Whatever the case may be, you'll need to take them off of the stove first. Remove the knobs properly so you don't break them in the process. The knobs on most Frigidaire stoves and ranges are removed and replaced in the same manner, no matter what model you own.
Turn the knobs into the "Off" position. Push in on the knob and rotate it clockwise until the marker is lined up with the "Off" setting.
Grasp the knob with your thumb and forefinger. Hold the knob firmly so you have a good grip.
Pull the knob straight toward you to remove it from the shaft.