Turn off the grinder and unplug it from the electrical outlet to prevent accidental power demand when replacing the wheels.
Loosen the wing-nut on the eye shield and raise it up out of the way. Loosen both the tool rest and the spark guard and move them out as far as possible. Removal of the tool rest and spark guard is not required.
Remove the retaining screws from the side cover using a Phillips head screwdriver.
Grasp the two retaining nuts holding the wheel to the arbor with an open-end wrench on the inside nut and a box-end wrench on the outside nut. Hold the inside nut stationary while turning the outside nut (clockwise for the left wheel, counterclockwise for the right wheel) with the box-end wrench. Remove the outside washer, the wheel, the inside washer and the spacer.
Be sure the replacement wheel is the correct measurement to accommodate the Dewalt grinder. Install the spacer first onto the arbor. Install the inner washer making sure the concave side of the washer is towards the wheel. Install the wheel and then the outside washer, again making sure the concave side of the washer is toward the wheel. Replace the nut and tighten. Do not over-tighten the nut or you can damage a grinding wheel by cracking it.
Replace the wheel cover and retaining screws.
Adjust the spark guard to 1/16 inch from the new wheel and tighten. Adjust the tool rest to 1/8 inch from the wheel and tighten. Adjust the eye shield to the desired position. Plug the Dewalt grinder into the outlet and test it.