Hyundai Repair: hyundai elantra thermostat, hyundai elantra gls, coolant temperature sensor

Question
location of and replacement tips for 2002 hyundai elantra gls thermostat

Answer
The thermostat is in the coolant housing on the transmission end of the engine.

First, remove the air box.
Then, unplug the coolant temperature sensor and pull the plastic cover off the thermostat housing.  
Finally, remove the two 12mm nuts and take the housing loose.
When installing the new thermostat, install the thermostat with the alignment protrusion matching the one in the housing.