Tumbling down

The future is a boulder tumbling down a hill. It is a force of nature guided by gravity. It will invariably collide with objects along it's terminal voyage, but will ultimately, invariably come to rest at the bottom of the slope. Along the way there are people shouting at the boulder to change course. Some helpfully suggesting that it follow a different path, some demanding that it violate basic laws of the universe and travel back up the mountain. Obviously this has no effect on history. There are others hurling things, sticks and stones at the boulder, but also to no avail, for the physical configuration of the hill and the pull of gravity alone will dictate the path of the rock. The only possibility then for altering the course of history is to re-arrange the rock, atom by atom from the inside out, so that when it comes to rest at the bottom (the end of time) as it will still inevitable do, it may be a different rock altogether (although still made of the same components). This is equally implausible, but not wholly against the rules. How shall we arrive then at the bottom?