If you mean the Appels pedals that control each division's reeds/upperwork windchest, try right clicking the control and unticking the Always On option. Make sure you do that for very screen.
Then Cancel should turn them off.
However, I don't think the sampleset allows master registration buttons to control the Appels, no matter what you do. You can hook them up to 4 toe studs or pistons to toggle them French style, or leave them Always On and just change the speaking stops with pistons English style.