If your standing facing your car with the hood open,
1) look for a radiator hose. there are 2 of them. look for the one on the left side. it should lead from the bottom of your radiator to mid left side of your engine block.
2) remove the hose from the neck which is connected to the engine block.
3) remove the neck, it's held on by 2 10mm nuts.
4) remove thermostat and replace.
how it fits (the gasket goes around the rim of the thermostat, not after it like the picture might illustrate)