isn't it just one button?

Yes, there is one button that plays the same note on the push and the pull. I think it is the one in the center of either the inner row or the middle row. All you do is retune that one button.

i think that is an 'extra' button

so you take it out and move all the other ones
down one, and you have one blank one at the top

wle.

This might help. Then again, maybe not. Perhaps somewhere else on this site.

Yes, it does help - I remember now that I look at that chart.

On the middle row, there is a note that plays C on both the push and the pull. All you have to do to de-club it is to change the C on the pull to a D. That's all it takes.

-David

Glad it helped. I figured it would, but it confused me.