For the full transformation to work, Ashley's skull had to be altered to be more like that of a bull. But the three things that even the technology of the twenty-sixth century was afraid to mess with were the brain, the eyes and the connection between them.
The solution was the careful removal of the skin from the skull followed by the application of a chemical that dissolved the skull without harming the eyes, brain or nervous tissue. A complete new skull, including teeth, built out of bone material engineered to be compatible with Ashley was then put into place. The muscles of his head that moved his jaw and his eyes had been set aside during the process and were then replaced, enhanced to work with his new, longer jaw. A cloned tongue was implanted. Very carefully the distance between his eyes was increased to allow for the muzzle between them. The sensory tissue of the nose had also been separated, and was now replaced in his new, larger nostrils along with new cloned tissue. The fiddliest bit of all was replacing the tiny bones in the ear. Nanites then propagated genetically compatible skin over the new skull and bovine ear-flaps were attached. Buds were put into place that would later grow into horns. The whole process took about twelve hours.
Seeing the naked brain always freaked Dr. Erlanger out a little, because she knew her own brain had stood out, equally exposed and vulnerable, in her transition from human to goat-woman. The finished process also looked a little creepy, as the new skin was hairless. What lay on the table was a being hairy below the neck and hairless above it, with an ambiguously gendered human body and a bull's head. The human and bovine elements had not been brought into harmony as they would be in a true minotaur.
But they would be tomorrow, body sculpting day.