Indicator switch MK 2

Hi All, Is it possible to fit the later indicator switch ( the one that has the white plastic ring which cancells it ) to the earlier steering column ? I think that I have done it in the past,but my memory is not that good any more !!

I seem to remember that one has to remove the steering wheel to get the ring to fit , unlike the early ones that just fit on the side with 2 screws.