First, thank you for your help!
Actually, recoding is the feature which I was looking for. It was however impossible for me to retrieve this information from any documentation or other source.
Interactive binning is nice, but obviously designed for continuous data and less suitable for ordinal/nominal data (although I got it working as well the way you suggested initially).
NB: as a user of the German language version, it is also many times impossible to actually apply the guidance found somewhere or in the documentation - if you find it at all. You have to switch your JMP to English first, then locate the feature you want to use, memorize it, switch back to German and then navigate again to the place. The German translation in the frontend is very cryptic to understand and the manual only available in English....