Get a bunch of 1-inch dowels, cut in lengths a little wider than your safe. Put the safe on top of four or more dowels , then you can roll the safe forward on top of the dowels. Pull out the back dowel and put it in the front of the line as the safe moves forward.
Be careful! This little technique does not work well on sloped floors, and of course the danger of momentum is a serious one. So take it very, very slow.
pax