I have a suggestion you can try out, but I'm not a hundred percent on this, so definitely make a full back up and don't delete any original media before doing this.
It's possible to click on your bin(s) and export them as .ALE files. Then from the finder (mac), open them in Text Edit (or Wordpad Windows) and change the FPS from 29.97 to 23.976. Save.
Make new 23.976 project, import bins, recapture at 23.976 and see what happens. Might be worth a quick experiment with just a sequence bin and one capture bin at first to see how it goes and if the edits line up.