Thermostat, Remove and Install (X 16 SZR)
Remove, Disconnect
Remove lower coolant hose from radiator. Collect escaping coolant.
Remove coolant hose from thermostat housing.
Remove rear toothed belt cover - see operation "Rear Toothed Belt Cover, Remove and Install (X 16 SZR)".
Remove thermostat housing (1) from cylinder head. Remove thermostat (2) from cylinder head.
Clean
Remove gasket remnants and clean sealing surfaces.
Install, Connect
Insert thermostat (2) with new seal ring into cylinder head and attach thermostat housing to cylinder head - tightening torque 10 Nm / 7 lbf. ft.
Install rear toothed belt cover - see operation "Rear Toothed Belt Cover, Remove and Install (X 16 SZR)".
Attach coolant hose to thermostat housing.
Install lower coolant hose on radiator.
Top up cooling system - see operations "Cooling System, Top up and Bleed" and "Cooling System, Check for Leaks".
Remove, Disconnect 
Clean 
Install, Connect 