dig six holes in the ground 3 on one side 3 on the other, the same space away from each other in a square pattern.
now to secure to the concrete block, drop metal rods about half a foot long into the holes in the concrete blocks, and then in the wood structure in the six parts where the blocks are on the picture, drill holes matching the width of the metal rods and drop the wood structure onto the metal rods with the holes and the metal rods on top of each other.
then place a flat piece of wood on top of that and then nail that down theirs your 