88 Jeep Cherokee Humm V Style How Do I Change The Fluid In The Reservoir In 88 Jeep Cherokee Wagoneer?

How do I change the fluid in the reservoir in 88 Jeep Cherokee Wagoneer? - 88 jeep cherokee humm v style

My jeep keeps over heating and I think I have very little liquid in the tank. It warms and died while I spray water and pulled the blanket ..... I'm going to be very new and do not know much about how to fix things. I need to know is how much of what is added to the reserve and how do I do? Also some other explanation for my overheating would be helpful, thanks:)