There is no drain cock on the '07 G6 GT. The easiest way to drain is from the water pump connection at the bottom passenger side of the radiator.
The 1991 Pontiac Grand Am radiator drain plug can be found on the bottom of the radiator. The radiator drain plug will be in the center of the radiator bottom.
on the radiator
In order to drain the radiator on a 2004 Pontiac GTO it is necessary to pull the lower radiator hose off. There is not a separate drain plug on this radiator.
The 1992 V-6 Pontiac Sunbird radiator drain plug, is located on the bottom of the radiator. The drain plug can be removed with a 5/8 socket.
The radiator petcock drain on a 1999 Pontiac Bonneville is on the bottom of the radiator. Look for a small black plug that looks like the plug found on a thermos or cooler.
Look at the lower or rear of radiator
It is on the bottom of the radiator on the drivers side.
Should be at the bottom of the radiator logically...
drivers side bottom right of radiator remove shield and look for plug
If it does not have a drain plug, just simply remove the lower radiator hose.
there may not be one if there is it is on the bottom if not you just remove the bottom radiator hose to drain
the rad drain plug is located on the drivers side behind the front bumper