Adjust parking brake?

I've noticed my parking brake is starting to slip on steep hills. How would I make the brake hold tighter?

Rear brakes could be worn

or an adjustment

You need to access an adjusting behind the e-brake lever.

1. Raise rear tires off ground
2. Pull parking brake up 1 ONE notch
3. Tighten adjusting nut until there is slight drag on the rear tires

proper adjustment -- rear brake fully engaged @ 6-10 clicks

my brake is i believe 4-7 clicks...though anything works.