Follow the top radiator hose over to the engine and where it connects to the thermostat housing. There should be two bolts holding the housing to the motor. Remove the housing and replace the thermostat and gasket. The larger side of the thermo goes in the engine.
Take the engine cover off, and there are three plugs in the front of the engine and three in the back. They are not that difficult to get to. The hardest part can be getting the boots off - be careful not to rip them or you will have to replace the wires as well.
Either something is wrong with the key or there is something wrong with the switch. You can try to spray some WD-40 or something like it into the switch and wiggle the key to see if you can get it turning. Otherwise you may have to replace the ignition switch.