i just did mine half way because i was missing a tool. first off wait till your car cools down then down on the lower right hand corner there is a drain. you unscrew the **** and it will come out below slowly. it takes a while. open up the radiator cap to let air displace. then you need to open up the engine block drain. that is where i missed a tool. the two plugs should be located on either side of your oil filter. thats where mine are on my 98 outback. and it needs a really large allen wrench. my biggest size wasnt even close to make sure you have. then let out coolent from there. then flush whole system with water until its clear. then take out coolent from resivor tank on side of radiator( overfill tank) after you do this close all the drains and set your heater to max heat. then start to add 50 50 antifreeze and water. it needs to be glycol something based. thats what my book told me i dont know how important that is. slowly add it to the radiator until it fills to the neck. then start the car until the thermostat opens and it will move all the fluid through the system creating more for you to put in. so it said to wait till the car cools down and then add more until it reaches the neck but i just went ahead and added it soon. and squeeze the hose going from the top of the radiator to the engine to expell any air bubbles. then add more to the radiator. also dont forget to fill the resivor to the lower fill line. then go ahead and drive it around for a little while and watch your gauge to make sure your temperature doesnt go up. after you drove it for a while let it sit and completly cool and go look at the over fill tank. when its cool it should be just above the lower fill line. so if its not keep adding your mix until it is. really easy. to do dont be scared.