Put on safety goggles and heavy-duty work gloves. Carpet nail strip edges are very sharp and easily can puncture skin.
Wedge the mini pry bar between the floor and the tack strip, then pull up. Expect the strips to break into small pieces as you pull up on them. As you pull up the nail strip, the only thing that should be left in the floor is the nail that was securing the nail strip to the floor.
Move the broken nail strips out of your way and continue working around the perimeter of the room until all of the nail strips have been removed from the floor.
Use the mini pry bar to pull up all of the nails stuck in the floor.