Pull the wiper blade and arm to lift it off the windshield, locking the wiper arm into the open position.
Disconnect the blade from the wiper arm. For mounted blades, remove the two screws that hold the arm and blade together. For arms that pop into the blade, press downward on the locking tab, then pull the blade off the arm.
Pull the insert out from the metal support ribs on the blade.
Insert the replacement blade insert. For open-ended support ribs, slide the new insert onto the rib from the non-lock side until the insert reaches the locked end and clips into place. For closed end support ribs, slide the new insert onto the rib through the first access hole, then press the insert at the lock end into an access hole.
Tug gently on both ends of the insert to ensure that the insert is secure in the support rib. Reattach the blade to the arm, replacing screws or popping the arm into place where applicable. Place the blade back into position against the windshield.
Lift the blade up and away from the windshield, locking the wiper arm into the open position.
Push upward on the wiper arm lever, then slide the blade forward to detach the arm from the blade.
Slide the old insert out of the blade, removing the two support ribs.
Add the two support ribs to the top grooves of the new insert. The driver side wiper will bow outward away from the blade's arm mount, while the passenger side bows in toward the arm mount. Add the temporary retainer clip on the locking end to hold the support ribs in position.
Slide the mount onto the blade from the non-lock end, until the temporary retainer reaches the starting claw. Pinch the top of the retainer piece to remove and push the starting claw into the rubber lock. Push the metal clip into the insert's groove under the support ribs on the non-lock end; types C and D do not use the metal clip. Tug gently on both ends of the insert to ensure it is secure.
Reattach the blade to the arm by reversing the steps for removal, and return the wiper arm to its position against the windshield.