Coat the machined areas of the spindle with grease and slide the new rotor onto it, taking care not to nick the new seal lip. Install the outer wheel bearing, the keyed washer, and spindle nut. Spin the rotor just to make sure everything looks good so far. If there is any grease on the rotor, clean it off with brake clean. The rotors are directional, so take care to get them right side for side. This is the passenger side and the slots in the rotor go "back" like in the picture. They are also engraved with an "L" and "R."