I just looked around further on YouTube and found one video where it looks as if the outline of the Calibrate control is NOT inside the MIDI control groupings. So
maybe the instructions are in error to some extent. Maybe if I get brave enough I'll install it, but I tend to avoid installing anything further on this old system out of fear something might crash it, at least until I'm very confident the plug will actually serve the purpose.
Thanks for the feedback guys, if you think of anything further please let me know....