Mazda Repair: 93 mazda 626 thermostat, upper radiator hose, coolant level

Question
How do you change the thermostat on a 1993 Mazda 626?

Answer
Locate the housing at the engine end of the upper radiator hose.

Drain about 1 gallon of coolant from the radiator
Remove the housing
Make note how thermostat is installed
Clean both surfaces
Replace thermostat and gasket
Re-fill coolant slowly to prevent an air lock, raising the front of the van on stands helps
Start engine and look for leaks
Run engine to normal operating temperature with heater on
Re-check coolant level, use 70 water/30 glycol mix