Unplug the power cord on your Craftsman miter saw and click the saw arm up to the highest position.
Remove the blade guard from the saw blade. Loosen and remove the nut holding the blade in place using a 3/8-inch wrench.
Grasp both flat sides of the blade with your hands. Carefully pull the blade off of the saw arm and set it aside.
Place your replacement miter-saw blade on the saw arm. Tighten it in place with the nut you took off.
Secure the blade guard back in its original location. Plug the saw back into power and test to confirm that you installed the blade properly. The replacement blade on your Craftsman miter saw should spin with ease.