To un-archive a Day Plan:

  1. Select the profile icon on the top left corner to go the Navigation Menu.
  2. From the Navigation Menu, choose “Day Plans”.
  3. From the “Day Plans” page, swipe left on the day plan you would like to un-pin.
  4. Tap the Thumb Tack icon.

This should un-pin your Day Plan, it should be removed from the top of the list, and will no longer show a thumb tack in the middle of the O.