You should disengage the two metal retaining clips from the mounting bracket on the windshield, remove the entire sensor from the windshield, clean the area of the windshield that contacts the windshield moisture sensor lens with a 5-/50 mixture of isopropyl, remove the plastic protective covering from the lens of the new sensor, place and install the moisture sensor back onto the windshield bracket, engage the two metal retaining clips to the mounting bracket on the windshield, connect the electrical cover and then secure the rain sensor module trim cover.