Let the engine cool and press down and twist the radiator cap to the left to remove it. Fill the radiator to the top and reinstall the cap. Check the coolant level in the overflow reservior and fill it to the fill line.
The headlight adjustment screw is located behind the headlight on a 2005 Chevrolet Impala. Open the hood and look behind the headlight.
It will be on the bottom right corner of the radiator under the hood
Counter-clockwise to open
If it is a plug -- turn it counterclockwise to remove If it is a "petcock" turn it clockwise to open
That is not a very good idea as you very well may damage the internal parts of the door. A locksmith is your answer.
Could be: Low coolant in the radiator - or - thermostat stuck open - or - heater core plugged.
Right below front of engine if you open hood look down it sits behind the radiator
First, find the motor for the sunroof. There will be a manual override on or around the motor that you can turn to close the stuck sunroof.
The drain plug is under the bottom left of the radiator. I find it much easier to just losen the lower radiator hose on the right side of the radiator. The drain plug tends to be hard to get open... KSH
There is a plastic drain valve on one of the bottom corner's of the radiator (facing engine) open valve and properly catch & dispose of coolant that comes out. You may need to use pliers to loosen drain valve. Tighten by hand.
Open the drain on the left side (driver's side) of the radiator. It is best reached from underneath. This will drain the radiator, most the heater and maybe half of the engine block. To drain the entire system the block drains have to be removed which is not practical in many cases because they are not easily accessible.
Open the petcock or remove the lower radiator hose from the radiator.