If you have a red block engine, there is for sure a block drain on the right side of the engine, near the rear of the block and under the exhaust pipe.

It is brass and looks kind of like a spark plug.

All you need to do is loosen it. If nothing comes out when you do, it is probably clogged. At that point, insert a piece of wire or a small screw driver to clean it out. If you screw it all of the way out, be prepared to lose all of your coolant because you will most likely be unable to get the plug screwed back in with the coolant gushing out.