Ok I'm about to start draining the coolant from the radiator but the engine drain bolt is pretty much inaccessable because of the turbo. How nessessary is it to unbolt this bolt and is there any other way to drain the coolant from the engine?

 

Just drain the radiator, then refill with water. Run the engine for a moment then drain again. Repeat a couple times if you want. That should get all of the old stuff out.

 

the way i did it was unscrew the drain plug...then detatch the hose that connects to the radiator....take a hose and shove it up the raditator hose...turn water on a nice constant flow...of course don't forget to take the top off the radiator....my car was overheating and i too couldn't do a good job because of the turbo....i guess it was clogged, becasue once i did this, problem solved...GL