Sorry Punt.....you might have meant the stat change?? Pretty straightforward. Obviously leave the job until the engine is completely cold....you don't want to burn yourself of damage any bolts that have expanded with heat. Remove the top pipe from the rad......or from the stat housing. This is my choice, as the top rad pipe is above the air filter, and I don't want to soak it in coolant, and I can't be bothered to remove it! So, top pipe off, then remove the temp sensor, then unbolt the stat housing. Put it all back together and top the coolant up 50:50 mix. I got some distilled water from Halfords today, tap water can lead to deposits in the system over time.