Clean the mating surface of the motor (A) and the gearbox.
Apply a thin coat of silicone grease to the new O-ring (B), and carefully fit it on the motor.
Apply silicone grease into the motor shaft (C).
Install the motor on the gearbox by engaging the motor shaft and the worm shaft (D).
Before tightening the bolts, turn the motor two or three times to the right and left about 45 degrees. Make sure the motor is evenly seated on the steering gearbox, and that the O-ring is not pinched between the mating surfaces.
Install the removed parts in the reverse order of removal, and note these items:
Make sure the motor 2P connector and torque sensor 3P connector are properly connected.
Make sure the motor and EPS wires are not caught or pinched by any parts.
Reconnect the negative cable to the battery.
After installation, start the engine, and let it idle. Turn the steering wheel from lock-to-lock several times. Check that the EPS indicator does not come on.