Remove the Kohler faucet handle by unscrewing the screw under the handle lever with an Allen wrench, and then pulling the handle off. It will slide off once the screw is taken out.
Unscrew and remove the escutcheon, a round nut on the end of the faucet underneath the handle, by turning it counter-clockwise. Unscrew the two screws in the front plate under the escutcheon with a screwdriver and remove the plate.
Unscrew the screw on top of the adapter on the end of the volume control knob and pull the adapter off.
Unscrew the bonnet, if your shower has a bonnet. This is a round-shaped nut right on the end of the faucet. Turn it counter-clockwise to unscrew it.
Pull the volume control valve out of the shower by hand. If your shower faucet trim plate is preventing you from accessing the volume control, remove it by unscrewing the trim plate screws with a screwdriver, and pulling it off the wall.