1996 Chevy Beretta Flushing radiator

I'm trying to flush the cooling system. According to my "Chilton's" manual I am supposed to remove the engine block drain plug and completely drain the coolant from the vehicle. Well unfortunately Chiltons doesn't provide much in the way of diagrams anymore and their descriptions are limited (if any). Can you tell me just where I might find this plug? An even more confusing step is to disconnect the the heater hose that connects the cylinder head to the heater core and connect that end to a fitting on the firewall. It goes on to etell me to connect a water hose to the hose to the heater hose that runs to the cylinder head. Well if I connect the hose to the firewall - how on earth am I supposed to connect a water hose to it for flushing? Any help would be greatly appreciated