radiator petcock location on 2006 Buick Lucerne

Where is the radiator drain petcock located and how do I get to it

Asked by for the 2006 Buick Lucerne
The radiator drain petcock is usually located at the bottom of the radiator on the lower tank area, Only open this when the engine is cold.
You will have to access from underneath the vehicle and it looks like a small pipe (3/8") with a cross that you turn on and off like a garden spigot.
Is the petcock on the passenger or driver side and can you reach it from above or underneath ?? Thanks