GMC Repair: Brake Specs, 4 wd, star wheel

Question
My brake light came on on my dash, i have been told that it means I need a rear brake adjustment. I need to know proper procedure for doing this.   I have a 1988 Jimmy 4 wd  ASAP ITs snowing. T Y  

Answer
helll cindy jack the rear of the truck up get a brake adj. tool and you will see a place to put it in the back of the drum plate . turn the star wheel up and till the wheel stops sping with the brake light on it means you have a problem in the brake system not adj. if u need more help just let me know amd i will help u pete