2006 Pontiac Grand Prix Draining coolant

Engine Cooling problem
2006 Pontiac Grand Prix 6 cyl

I just took off the plastic splash covering and I am not sure where I drain the coolant. My father says that you loosen up a screw that is on the radiator on the driver's side to drain the coolant. The problem is, the screw I believe that I should loosen up is under a metal cover that is used to support the radiator.

So to sum it up here are my two questions:

1. Where do I drain the coolant from?
2. Is this metal support a known problem for coolant replacement?

Thanks in advance.