In another thread, I discussed the wiper blades. In this, I will explain how to remove the wiper arm. The arm is a proprietary item that changes whenever the body style changes, so they are not interchangeable between years, unless the cowl and hood configuration remains the same. The difference between years is the angle of the arm in relationship to the blade, and how it retracts when it parks. In 1967 Pontiac Motor Division introduced the first hidden wiper arms, by removing the cowl screen, and making the hood longer to leave an opening at the bottom of the windshield where the arm & blade assembly would "hide" when in the parked position. Eventually the rest of the GM line would adapt this design feature. Even though many arms might fit on the wiper stud, never assume that it will function properly if it wasn't designed for your vehicle.