Remove all electrical power from the circular saw. Unplug the saw's electrical cord from the wall outlet.
Locate the blade-locking mechanism. This is typically a metal button approximately 3/8 inch in diameter and a ½ inch long. The blade lock button is generally located on the opposite side of the saw blade on the saw housing.
Rotate the saw blade while pressing the blade lock button inward. The button will depress when the slot in the motor shaft aligns itself with the button shaft. Keep holding the button in once it fully depresses.
Fit the correct size end wrench or the Skilsaw blade wrench over the blade's center shaft bolt. Turn the wrench in a clockwise direction. The center shaft bolt on a Skilsaw is a left-handed thread.
Loosen the bolt with the wrench. Remove the bolt with your fingers. Pull the thick blade washer from the motor shaft.
Remove the blade from the saw arbor.