ECT Sensor 1 Replacement

Drain the engine coolant (see COOLANT CHECK )
Disconnect the ECT sensor 1 connector (A)

Fig 1: ECT Sensor 1 Connector, ECT Sensor 1, O-Ring With Torque Specification
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Remove ECT sensor 1 (B)
Install the parts in the reverse order of removal with a new O-ring (C), then refill the radiator with engine coolant (see COOLANT CHECK )