Replace the small molding on the left side.

Apply grease to the cog, bar, the rack under the wiper assembly, and any other places where the parts slide against each other.

Replace the lever. Ensure it hooks into the end of the white sprung cog assembly. Ensure that the lever moves smoothly back, pushing the cog on the other side out, and then springs firmly back into position.

Replace the top cover and secure it with the 4 screws.

Replace the front cover.