And then, put the lens to a camera in the 2-o'clock position seeing that the meter coupling shoe engages the coupling ring pin out of pentaprism unit, and turn it counterclockwise till it clicks and stops.
When you finish it, turn the aperture ring down to minimum and then, up to maximum.
By doing this, the aperture index of the lens is to send to a camera.

When you take the lens off, set the aperture at "5.6" as you did previously, and then with pushing the button, turn the lens clockwise.