I just changed my radiator hoses and thermostat a month ago. same year and model as yours. the plug on the bottom of the radiator is a small white plug. unscrew it, and pull it away from the radiator. it will not come out all the way, but fluid will drain out. it is rather difficult to direct the flow, so be on ground you do not mind getting soaked in coolant fluid.
if nothing still comes out, you were running on an empty radiator, which is not physically possible. so something be wrong. best of luck. hope this helps.
• 81 J20 8400#
"The existence of flamethrowers is proof that someone,
somewhere, said to himself, "I want to set those people
over there on fire, but I don't feel like walking over there to do it."