Need assistance ASAP...

I'm trying to drain the coolant out of my '88 Trans Am GTA (5.7 TPI). There is water mixed with the coolant due to an overheating issue over the summer and water being the only thing accessible at the time to take the car home. With the temperature dropping rather quickly, I would like to drain everything ASAP. Can anyone tell me if there is a drain plug on the block and if so where? If not, what would be the best way to drain out the coolant from the engine? Any help would be greaty appreciated. Thanks in advance.

Remove the lower hose, one good way, look for plugs in the lower sides of the block also.