Remove the shower head from the water pipe.
Remove the small plastic flow restrictor disk inside the Kohler shower head, using a thin piece of metal. Remember which side of the disk is facing outward as it must be replaced in the same position.
Rinse the shower head under water to remove any debris. Use a small pin to clear the holes on the flow restrictor disk. Make sure you have plenty of illumination in your work area.
Place the shower head in a bowl of warm white vinegar for two to three hours to remove any hard deposit buildups that may have caused the low water pressure. Scrub the shower head with a toothbrush after the vinegar bath.
Reinstall the flow restrictor disk and reattach the Kohler shower head.