2012 Cascadia radiator drain port

Can somebody explain me how to drain the radiator on 12 Cascadia ? do I need to take off the whole outlet port by using 27mm wrench ? if yes then why there is that ½ inch hose outlet end?
thanks

 

update:

how to drain cooling system of epa 10 Cascadia with dd15.
if you need to change something on engine (water pump, thermostat, ..) there is a drain plug on left side of engine block. turn it a little, hook up a hose and turn it again until you see coolant is coming out. if you need to drain the radiator then with wrench turn the drain port until you see the coolant is coming off. hook up 1/2 hose and turn it 1 to 1.5 full turn and stop. if you turn more then that the entire piece will come out and you will have a flood.

 

I am changing the coolant because my friend added regular coolant in the system. I had rotella elc before and now it is some kind of mix of two different coolants.

 

autozone brand yellow coolant was added on top of red rotella elc. he wanted to pay for new coolant but I did not let him to do it. my friend has much much higher value than the cost of new coolant ..

 

first I drained the engine block and some metal shaving came off with coolant. I think they were there since engine was assembled.

 

190-200 f is normal for your engine. don't do anything. what oil pressure reading do you have at idle when engine is 90-200f ?