Remove the door trim panel and watershield. Unbolt the window glass from the regulator, push the glass all the way up, and tape it to the door frame. Remove the window regulator-to-door and track mounting fasteners, noting the different mounting fastener positions for the Challenger compared to the Charger and 300 models, and loosen the bolts for the regulator motor without removing them. Unplug the electrical connector and remove the regulator from the door. Installation is the reverse of removal, ensuring to tighten the glass retaining fasteners to the specified torque. If the regulator has been removed or replaced, or if the battery has been disconnected, a relearn procedure must be performed for the Driver's Door Module or Passenger's Door Module to operate the window correctly. Ensure the battery is fully charged or the vehicle is running, and all doors are completely closed before proceeding. If the regulator has been replaced, use a scan tool to activate an ECU reset for the appropriate door module, which will set a calibration missing OTC for that module. Lower the window glass to its lowest position and hold the down position button for an additional two seconds, then raise the window to its highest position and hold the up position button for an additional two seconds. Check window operation, and if the regulator was replaced, check for any stored DTCs, ensuring the OTC for missing calibration changes from "active" to "stored." Clear the code and verify window operation, and it's advisable to check for any stored service codes in the BCM, clearing them and confirming window functionality.