Mate , its pretty easy, u need to remove the engine cover and you will see the top radiator hose conects to the thermostat housing, you will already have drained the fluid for the radiator so all you have to do is remove the 2x bolts holding down the housing and you will find the thermostat inside, just remember to put the thermostat back in the right way, you should also replace the gasket (just a few dollars from supercheap). Dont forget to use the right type and quantity of coolant as well as bleed the air out when your done ( via the bleed screw at the top of the thermostat housing) if you need more info check out the how to section for 'flush cooling system' which should answer any other questions you may find along the way. Hope this helps,