Disassembly of the thermostat would have an adverse effect, causing a lowering of cooling efficiency.
Drain engine coolant so that its level would be under the thermostat height.
(Refer to Cooling System - "Coolant")
Remove the radiator lower hose (A).
Remove the water inlet fitting (A) and thermostat (B).
Tightening torque :
18.6 ~ 23.5 N.m (1.9 ~ 2.4 kgf.m, 13.7 ~ 17.4 lb-ft)
Place the thermostat with the jiggle valve (C) upward.
Fill with engine coolant.
(Refer to Cooling System - "Coolant")
Start engine and check for leaks.