Before you replace the Wiper Arm, put a marker or masking tape on the Wiper Blade's spot, and then disconnect the washer hose. Take off the cover that is on the Wiper Arm nut, then unscrew the nut. Make sure to use a battery terminal puller to take off the Wiper Arm from the Drive Shaft, after which you should use a wire brush to clean the knurls. Place the Wiper Arm so the blade lines up with your previous mark before putting it onto the Drive Shaft to install it. Add the nut to the Drive Shaft, tighten it with 30 n.m (22 lb ft) force, then put the cover back on and attach the washer hose. When you are done, take off the locating mark or masking tape from the windshield and test the wipers to ensure they work well.