After some time, the windshield wiper blade components are susceptible to cracks and wearing away. This is accomplished by lifting the wiper blade assembly off the glass. Then press the release lever and slide the blade assembly off the hook at the tip of wiper arm. Squeeze end rubber prongs on the blade element together then slide it out of frame. Pliers may be needed for this step. Compare new element against old for length, design, etc. Some replacement elements have a three piece design that is held together with several small plastic sleeves. Keep these sleeves in place, as you start sliding it into frame. Remove each of plastic sleeve as they reach frame . Slide new element into frame with notched end last and secure clips into notches on frame. Lastly, reinstall blade assembly onto arm, wet windshield and check for proper operation.