Offset surface

I am trying to reproduce the red shoe (see the link)

http://www.npowersoftware.com/nurbs/pntutorials.htm

I have completed the shoe body but don't know how to go about reproducing
the white pattern on the irregular surface.

Remember the pattern goes all around the shoe.

Can anyone help?

 

So when you say 'offset' and 'trim 2D surface' commands , where do I find
these?

 

I have looked at the file.

I have offset the surfaces but how do I draw on the surfaces to trim them?