The self-adjuster type will have a very fine-toothed star wheel and some linkage or a cable connecting it to the top of the brake at the anchor pin just above the wheel cylinder. It adjusts when the brakes are applied in reverse, but only when there's enough shoe movement to indicate the lining has worn.
To adjust that one, go through the slot behind the starwheel with a screwdriver or a brake spoon, and tighten the brake until you get a firm drag, NOT a lockup. Then loosen the starwheel one full turn, about 10 clicks. Don't worry if there's still a bit of drag, as the shoes will self-center the first time the brakes are applied. Just loosening enough to get free movement instead of a full turn will result in the brakes dragging as they heat up.
Jerry
