The wiper arm is fixed to either the screw, which goes directly into the wiper arm drive shaft or a nut, which screws on the end of the shaft. The angle of wiper arm should be remembered in order to fit back on the output shaft of the linkage assembly properly. The screw or nut is then unscrewed and then the wiper arm is taken off the output shaft of the linkage assembly. To install, simply position the wiper arm over the splines on the output shaft of the linkage assembly and screw or nut. The 1988-89 626/MX-6 and the 1986-89 RX-7 have letters inscribed on the component to which the wiper linkage connects with the driver side arm being marked DL and the passenger side arm being marked PL so as to ensure that they are fitted in their correct places as they are incompatible.