Hi there,
Here is the way how it make the head. Sorry. The process notices are in Chinese.

Hi there,
Below is the link to a China Sketchup discussion forum.
http://www.sketchupbar.com/forum-viewthread-tid-15935-extra-page%3D1%26filter%3Dtypeid%26typeid%3D14-page-2.html

It's amazing to see someone can draw so detailed human head in Sketchup.
Could anyone know other ways to make a similar one and so detailed in a simply way in Sektchup?