How do you change the heater core in a 1986 Ford Ranger?

You need to go to a car parts store, and get a repair manual for your car. They cost about $16.00 Or, go to a Public Library. WAA

An actual answer can be found here: http://www.fordrangerforum.com/4-cylinder-tech/2899-1986-ford-ranger-heater-core.html

Sorry your question was answered by such an idiot.