How did the Aztecs get their stones for building?

The 16th century Florentine Codex gives us excellent evidence, both through images (see picture) and text (follow link below), of how the Mexica (Aztecs) worked stone from rocky hillsides (such as from the tributary province of Malinalco, around 25 miles south of Tenochtitlan - we know from the Codex Aubin that the Aztecs quarried stone from there). Using simple, but tried-and-tested techniques such as driving stone wedges into cracks in the cliffs, men would have hauled off large stones using ropes and rollers. With the help of large towing canoes in the canals alongside, they could be dragged along the causeways leading into the capital. Richard Townsend sums up the process:-
The technologies of quarrying, transporting and working large monoliths were already well developed in Olmec times, c. 900 BC, and had reached new levels of achievement in Teotihuacan (during the early centuries AD) where sculptural monuments weighing up to 40 tons were brought from distant quarries (presumably using log rollers) to be set up in the ceremonial center. The Aztecs acquired the tradition of monumental stone carving first from Atzcapotzalco, and later from the Huaxtecs of the Gulf Coast.

Aztec stone cutters, Florentine Codex Book 10