This is a bit different — the tools are now stored in CSV files (do Help | About | Open Data Directory to access the carbidecreate/tools directory), and it is first necessary to add a New Library:
after clicking on the “New library” button you will get the “Create new library” dialog:
make appropriate selections (note that certain endmills only appear in certain materials — at this time, MDF has the most complete listing — further note that one aspect of this is the suitability of an endmill for a given material — a #251 should not be used for metal work, so does not appear in those libraries) and click “OK”. Note when naming that the machine type and material will be added as a suffix — a consideration to avoid department of redundancy department naming:
EDIT: note however that it is still required as of this writing that one use a period as a decimal separator both in the OS and in CC.