How does the Audi A1's parking assist feature work?

I just purchased an Audi A1 and I'm having trouble understanding how the parking assist feature works. Can someone explain the steps to use it properly?

Park assist on the Audi A1 is easy to use, but it may take some practice to get comfortable with it. First, activate the system by pressing the park assist button on the driver's door. Then, select reverse gear and the park assist screen will appear on the MMI display. From there, let the car guide you by following the on-screen prompts. And remember to keep your hands on the steering wheel at all times.