UMAT Dr Huang's Crystal Plasticity Code: help

Dear all,

I want to implement Dr Huang's code for polycrystals. I am stuck at two issues. 

1. How do we define the orientation to each grain separately in the code ? (I believe we need to do it in texture.txti ?)  I am not able to understand the texture.txti file.

2. What else would be different for a polycrystal CP umat implementation?

I apologize if my doubts are too basic. Please assist.