Qinshihuang just ordered the craftsmen to build the statues for him. They were not built from stones, they were built from earth actually.

Hi.When I was done reading your question,I wrote down some research. By the way,they were not made from stone.I found out that 2,200 years ago, an emperor named Qin Shi Huang,demanded for these professional craftsmen to build sculptures because he believed it would guard him in the afterlife as he's rested in his tomb. But it turned out to be 700,000 people to make them. So then before actually making them, they have decided to get this "yellow earth" source from around Qin Shi Huang's Mausoleum. When the workers finished, it turned out to be over 1,000 sculptures built.