Leaking power steering pump

During an inspection, it was reported to me that the power steering pump on my 2000 Corolla was leaking. That surprised me becaue I have owned this car for 50,000 miles, but I have yet needed to add any power steering fluid.

Avyway, the inspector said that I cold wash it clean with Gunk and if it didn;t visibly leak, he could pass it. I bought a quart of Prestone Power Steering Fluid + Stop Leak. I'm figuring that it will work best for me if I somehow drain out enough space to accommodate most of the contents of this container. My questions regarding my attempted repair are, 1) about how much power steering fluid is there in my power steering system, and 2) how can I most readily or practically drain it to make space for the stop-leak enhanced replacement fluid?
I siphoned as much as I could out of the fill reservoir,which wasn't much and replaced it with Prestone Power Steering fluid with stop-leak.. Someone stole my nice gooseneck inspection camera with a 4" color viewing screen, so I have no way of looking at the pump close enough to see what indications there are of leakage or where. It is buried so deep that I couldn't even get a good shot at it with the Gunk, even after I removed the serpentine belt.

The reservoir and cover say to fill to the proper level bbut it doesn't say what the proper level is. What is the proper fill level?