In spite of blistering heat that turned me into a mass of sticky goo, I managed to remove the wood deck upon which the concrete floor was poured. All things considered, the operation did not take particularly long nor was it notably difficult. The key was to get the 2x8's out in such a way that a sheet of plywood did not land on one's head.
So far the concrete deck seems to be holding. So now I need to finish the foundation drain and fill in around the cellar. Then we can start on the building!