Classic Mustangs that were equipped with automatic transmissions featured a floor-mounted shifter arm. At the tip of the shifter arm was a safety button. To shift the transmission out of the "Park" position or to the "Reverse" position, the button must first be depressed. The button is made of sturdy plastic, but if the hidden middle portion of the button breaks, the button will stick. Fortunately, replacement buttons are available and fairly straightforward to install.
Remove the set screw from the front of the shifter handle by turning the screw in a counterclockwise direction with a hex wrench.
Lift the shifter handle straight up to detach it from the shifter arm.
Turn the handle upside down.
Lift the shifter button out of the center of the handle.
Insert the new button into the handle.
Lower the handle onto the shifter arm, ensuring that the set screw hold on the handle aligns with the hole on the shifter arm.
Insert and tighten the set screw into the shifter handle with the hex wrench.
