When the wipers no longer clean well, the blades are probably worn or cracked.
Replace them.
To prevent damage to the wiper arms and other components, do not try to sweep the wiper arm by hand.
Do not bend the blade rubber unnecessarily when replacing it. Otherwise, the metal stiffener in the blade may deform and the windshield wiper operation may be adversely affected.
When raising both windshield wiper arms, raise the driver's side wiper arm first. When lowering the wiper arms, slowly lower the wiper arm from the passenger's side first while supporting it with your hand. Forcefully lowering the wiper arms could damage the wiper arm and blade, and may scratch or crack the windshield.
Raise the wiper arm.
To prevent damage to the windshield let the wiper arm down easily, do not let it slap down on the windshield.
Slide the blade component in the direction of the arrow while pressing the wiper arm tab to remove the blade component from the wiper arm.
Pull the blade rubber in the direction of the arrow and slide it to a position where the blade holder groove can be checked.
Pull the end of the blade rubber from the blade holder groove in the direction of the arrow and remove the blade rubber from the blade holder.
Insert the end of the new blade rubber into the groove of the blade holder until it contacts the end of the blade holder.
After pulling the blade rubber in the direction of the arrow and sliding the blade rubber to a position to check the blade holder groove, slide the blade rubber end in the opposite direction.
Make sure that the blade rubber is correctly installed to the blade holder.
Align the blade component projection with the wiper arm notch.
Slide the blade component and install it to the wiper arm.
Slowly lower the wiper arm onto the windshield.