First thing is to remove header tank cap then get under neath the car and open the drain bung at the bottom of the radiator (passenger side) to release the old coolant.Once you have deposited most of thie coolant on to your arm/driveway now is a good time to think about getting a drip tray!! Flush the system through several times with water to make sure as much of your old coolant is removed from the sytem.How many times have you wished for that drip tray? Once you are happy that the old coolant is out refit the drain bung you know the red one that came out in your hand with frustration after being stuck in for ages.Make up your coolant to the dilution that you want then add to the system via the header tank until you reach the required level on your header tank.Close the cap on the header tank,start the engine and put the heater up to hi.allow the engine to run for about five minutes then switch it off.Carefully remove the header tank cap and 'burp' the system for any airlocks then top up as required with coolant trying not to burn yourself in the process.I hope that helps.