I have a dozen 24-page books where the PMS is used as 80% and I need to globally change it to 60. Note, I did not create a tint in the palette.
Start by creating a Tint swatch for the current value.
Use Find/Change > Object tab to locate objects filled or stroked with the percentage and change them to be filled or stroked with the tint swatch.
Edit the tint swatch.
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