Mr.Ho,
The ticket office of the pulley is located at the parking lot in the front mountain. The entrance of the pulley is located near to Badaling Bear Garden. The pulley will spend five minutes to take you to the North Fourth Tower of Badaling Great Wall. From the North Fourth Tower, you can continue to walk forward till you reach the North Eighth Tower.The cable car is located at the back mountain. Usually, most visitors will use the pulley or cable car to save their energy. It's up to you whether use it.