The mainstream view of our history has some massive unexplained mysteries. For example the ability of ancient people to work with massive slabs of stone in a way we'd struggle to do now even with modern machinery. Not just the Pyramids and Stonehenge, but the stone foundations at Cuzco and also Baalbeck temple which apparently has foundational stones estimated to weigh 1000 tons.
How would you do it?
Just get a stout log and a bunch of men and pry up one end of the stone and shovel dirt and debris under it.
Then pry it up again and repeat.
It would take a long time but eventually you could get it standing.