The thermostat is commonly found where the upper radiator hose connects to a "neck" on the engine, the thermostat is inside that neck housing, yes, you can do it yourself, you have to drain the radiator before you do so. Please do this with the engine cold. Just be sure that you make a mental note of how the thermostat is in the engine so that you will put the new one in the same way, be sure to replace the gasket on the housing as well.