Here ya go
There is a brake drum inside the rotor that the parking brake shoes contact. On the backing plate there's a rubber plug which will let you access a star wheel adjuster, just like regular drum brakes have. The plug is recessed a little and kind of hard to see.
What I did on mine was loosen the cable, then turn the star wheel until the shoes start to drag. Sorry, I don't remember which way, it'll either bottom out or the shoes will drag. Then I re-adjusted the cable. Now my parking brake pedal only goes half way to the floor and it holds good.