The tibetan sky burial involves the body being fed to vultures. Once the spirit leaves the body there is no longer any need for the body. The body (wrapped in white cloth) is placed on a platform of stones (in a fenced off area designated as a burial site). It is then unwrapped and sliced up with huge cleavers by a butcher (the Tomden), to expose flesh and bone. The butchers are often monks who specialise in the task of butchery. The butchers work methodically and professionally. Vultures are attracted by juniper smoke and the exposed flesh and begin to eat the body. The Tomden then returns to the body cutting off arms and legs and feeding it to the vultures.
The Tomden may work with other Tomden and throw pieces of flesh to the vultures. He also smashes and pulverises bones (with rock or sledgehammer), including the skull, feeding the brain (after it has been mixed with flour) and marrow to the crows and other birds, until nothing is left. The Tomden may also create skull bowls or thigh bone trumpets from the remains.
Sources:
http://www.alumni.caltech.edu/~pamlogan/skybury.htm
http://www.ciolek.com/WWWVLPages/TibPages/tib-burial.html
http://www.aroter.org/images/historical/amdo.htm
http://www.acs.ucalgary.ca/~chilton/Tibet.htm