Board Thread:The Quarters - Q & A/@comment-76.28.194.180-20140617051003/@comment-24150802-20140618102850

Check off the daily. That should make HabitRPG realise that the challenge has finished and that the daily should be allowed to be deleted. The megaphone icon on the daily should now appear broken. Click on that icon and it will ask you if you want to keep or remove the challenge's task(s).