Dave has a really good vid somewhere on the net on how to do this but…
With the paddle at 6 o’clock lift the lever to start flow.
Move the paddle clockwise gently until the flow stops(this appears to be about 9 o’clock on your vid.)
Lower lever to stop flow.
Use a small (2mm?) Alan Key to loosen the set screw in the wooden paddle, lift the paddle and reset it so that it touches the machine body.