How was this ancient granite block precision shaped?

Arthur Posnansky, Bolivian engineer and archaeologist who is considered the Czar of Tiwanaku & Puma Punku archaeology, believed these sites had an inception date of 15,000 years old based on celestial alignments… featured here are precision granite or diorite blocks from Puma Punku, about a 7 on the Mohs scale. How do you think these were shaped?