Well, you are on the right track:
First, you turn it to waste (rinse?) for about 30 seconds. Then to backwash. After you turn it to backwash, the sight glass will be clear at first, then go cloudy, and finally go clear again.
At that point you turn it to waste again for another 30 seconds and you're done.

Always run waste and backwash on high speed. Turn OFF the pump's power between switching between settings.