anti freeze flush

I like to flush the antifreeze in the car (S500). I know the capacity is 16.5L, and best ratio for me would be 60 water/40 antifreeze, so that would be 6.6L of pure antifreeze and rest would be distilled water
If I open the rad drain plug only a small % of existing coolant will drain which bring me to this:
where exactly is the coolant drain plug for the block? how do I make sure all of my coolant is drained? I also want to stick a garden hose in there and flush all the residue out... is it best if i remove the thrmostat so water can circulate the cooling system freely?
last but not least, once its all topped up, how do I bleed the cooling system?
anyone done it? I need details
Thanks



