first, let the car cool down. second take off the radiator cap. third loosen the little drain plug on the bottom of the radiator and let it sit there and drain make sure you have something to catch that coolant and dispose of it properly. after all the coolant is gone, tighten up the drain plug, make sure the coolant your using to refill it is 50% water and 50% coolant. after you fill it up, start the car without the rad cap on it and let it idle. the water pump should be cycling the coolant through the engine and as the coolant goes down refill as necessary. Oh and turn on the heat in the car put it on max heat. if it's not getting hot you have air in the system but if it does get hot you should be good. then after all that is done top off the reservoir if you need to and voila! your good to go!
