After six months of exposure to wind, rain and road sludge, the rubber blade on a windshield wiper can become cracked and worn. Instead of replacing the entire wiper system, some vehicle models allow for the simpler replacement of just the rubber part that actually cleans the windshield. These inserts are available at auto parts retailers. Use the catalogues in the wiper aisle to identify which blade fits the make, model and year of your vehicle.
Pull the wiper arm away from the window until it is in a locked, outward position.
Remove the old rubber by peeling it out of the blade.
Remove any locking clips on the wiper blade and feed the end of the new rubber insert into the channel until the new blade is positioned evenly on the wiper blade assembly.
Return the wiper arm to the rear window. Test the wiper by wetting the glass and turning the wiper activation knob to its lowest setting.