Removal of the wiper arms requires the use of a special tool, G.M. J-8966 or equivalent, which is generally available in auto parts stores. Insert the tool or a screwdriver under the wiper arm and pry the arm off the shaft, being careful not to scratch the paint. Disconnect the Washer Pump hose from the arm (if so equipped) and remove the arm. To install, position the arm over the shaft and press down, making sure to install the arms in the same position on the windshield as they were when they were removed. Raising the hood on most later models will facilitate easier wiper arm removal.