As the drum brake system on your vehicle wears, a lip develops in the drums just past the shoe contact area. This can sometimes make the drum difficult to remove. The only solution to this problem is to loosen the self adjuster and allow the shoes to compress inward. This provides the needed clearance to remove the drum.
Raise the vehicle with the floor jack and place jack stands under the frame to support the weight of the vehicle. This prevents injury if the floor jack fails and the vehicle falls. Remove the wheel using the lug wrench, and place the wheel and lug nuts out of the work area. This prevents tripping and loss of the lug nuts.
Remove the adjuster access plug from the lower back side of the backing plate. On some vehicles, this access isn't punched all the way through. Punch out the stamped steel tab with a hammer and punch. Remember to retrieve the tab from inside the brake system when the drum is removed.
Push the self adjuster arm, and release it from the self adjuster star wheel using a small screwdriver. While holding the adjuster arm off the star wheel, rotate the star wheel in a downward motion with the adjuster tool, until the drum is loosened from the brake pads. Slide the drum off the brake shoes.
