1. Check the condition of the brushes. Replace worn brushes. The brushes should also be replaced if the glass cleaning performance is insufficient. It is recommended to change the brushes annually.
2. To remove the brush, pull the brush holder lever away from the glass until the lever locks. Rotate the brushes by 90°, press the internal lock of the brush with a screwdriver or finger and remove the brush from the hook of the lever, bringing the lever out through the groove in the brush frame.