Remove air intake pipe and charge air pipe from intake manifold. Remove lower coolant hose from radiator - collect coolant. Remove coolant hoses between oil cooler and thermostat housing or oil cooler and connecting piece at cylinder head - collect coolant and engine oil.
Remove connection fastening bolts (1) from cylinder head. Remove thermostat with screwdriver from connection.
Clean
Clean sealing surfaces on connection and cylinder head.
Install, Connect
Insert thermostat with new gasket (1) and carefully drive in to stop with suitable pipe (2).
Attach connection with new gasket to cylinder head - 30 Nm/22 lbf. ft.
Install coolant hoses between oil cooler and thermostat housing or oil cooler and connecting piece at cylinder head. Install lower coolant hose at radiator. Install air intake pipe and charge air pipe at intake manifold.
Top up cooling system - see operation "Cooling System, Top Up and Bleed" and "Cooling System, Check for Leaks". Check engine oil level, if necessary correct.
Remove, Disconnect 
Clean 
Install, Connect 