How do I uninstall Korg audio drivers from a Mac
Typical - no sooner have I posted the question than we realise that the download also contains an uninstaller.

But, according to Korg's 2015.11.09 news


  We can inform you today that DS-DAC-100 and DS-DAC-100m are not compatible with El Capitan and advise you not to update your operating system until compatible versions has been released.


So we're stuffed anyway.