[raymo]

Being as there is no inbuilt clutch system on the SW motor focuser, so that the focuser can't be operated manually, you need to remove the single speed
focuser knob/wheel, and connect the motor directly to the shaft via the
flexible connector shown in your pic [ as posted by Imme], and modify the bracket to support the motor.[ The original kit comes with the necessary bracket]. You need the motor on the single speed side because if you
connect to the geared down side, even on max speed the focuser will move
glacially. On the single speed side the motor on its slowest speed will allow
little taps on the button to give miniscule movement for fine focusing purposes.
Its not a permanent mod because you can convert it back to its original set up in 5 minutes.
raymo