1. Park the ATV on a level surface and turn off the engine.
2. Locate the rear brake adjuster, which is typically located on the rear brake lever or near the rear brake caliper.
3. Use a wrench to turn the adjuster nut or bolt in the appropriate direction to tighten or loosen the brake cable.
4. Test the brakes by applying pressure to the brake lever or pedal. The brakes should engage smoothly and firmly without excessive play.
5. Re-adjust the brake adjuster as necessary until the brakes are properly adjusted.
6. Ensure the brake light is functioning correctly when the brake lever or pedal is depressed.