You need to clean all corrosion or contaminates from the steering knuckle bore and the hub and bearing assembly, lubricate the steering knuckle bore with
Wheel Bearing grease or the equivalent, install the O-ring to the steering knuckle, the wheel speed sensor to the wheel hub and bearing, the wheel hub and bearing and splash shield to the vehicle, the wheel hub and bearing mounting bolts and the nut and washer retaining the wheel drive shaft assembly to the wheel hub and bearing, connect the electrical connection for the wheel speed sensor and install the wheel speed sensor and brake hose mounting bracket bolt to the steering knuckle, the rotor and the tire and wheel.