Set the cabin heater temperature to as hot as it will go so that the coolant goes all the way through the system including the heater matrix, fill the coolant up to the max mark, keep the lid off the coolant bottle, start the engine, and let it idle to full temp, but keep an eye on the coolant level in case it requires topping up. Allow the cooling fan to cut in a couple of times to ensure that there is no air lock. Replace the coolant cap. Job done.
Well, job done my way any how!!!!!