Not quite, think you need to raise the front end a bit to help the coolant run out the drain on the block. It's located just above where the turbo connections are and you need to drain from here as well a the other places you mentioned then keep flushing till you get clear water coming out. Correct about putting the heater on hot to recycle the coolant from it too.
Mix I think is 50/50 so you'll need about 6 litres of straight coolant and carry some in a bottle in the car with you for a week or so after to top up as it settles and any air works its way out.
Think there is a full on guide on here somewhere about it too.

 

I'll add in: remove radiator and take to radiator place have it pulled apart and rodded.

Cheers

Justin

 

Id also grab yourself a ECUTalk if they are still available, the peace of mind mine gives me when out on my travels is priceless. Done a 5000k trip over Xmas and got as far as Airlie and not once over 92 degrees.

 

Hi,

You can put in a product to loosen sludge before you flush it, and take out the thermostat. It will stop the hose from flushing it. Put the thermostat in a bucket of water, as once in use the stuff on it will go hard when it dries out. Put it back in before you refill the system.

Regards B M

 

There is also a bleed at the back on the firewall above the connection points for the heater hoses - right behind the intercooler. Bugger to see but it's there.