How do I change the materials used in the Avatar?

[LucasRizzotto]

We want to create a custom look for the avatars in our app by changing the materials present, but there doesn't seem to be any available APIs for that and the vast majority of the classes in OVRAvatar have no documentation I can find.

How can we change the materials used in the hands or the body, for example? 

[MikeF]

materials are loaded in at runtime, so you'l have to reference them then modify the parameters through code or replace with your own material