Drain the engine coolant.

Disconnect the water bypass hoses (A), then remove the oil cooler (B).

Clean the O-ring groove and mating surface with the engine oil gallery cap and oil cooler.

Apply new engine oil to new O-rings (C). Install the engine oil cooler with the O-rings, then install the water bypass hoses.

Refill the radiator with engine coolant, and bleed air from the cooling system with the heater valve open.