Using the Ambush 2 mountain bike helmet is easy. First, adjust the buckle to ensure a snug fit on your head. Make sure the helmet sits level on your forehead. When riding, the helmet's ventilation system will keep your head cool. As for eyewear, you can easily integrate your glasses with the helmet. When it comes to maintenance, use a mild soap and water to clean the helmet regularly. Avoid using harsh chemicals as they may damage the helmet. Also, check the helmet for any signs of damage before each ride. If you notice cracks or significant wear, it's time to replace it. And remember, always follow the U.S. CPSC Safety Standard when using the helmet.