Reduced Stiffness Matrix

[kukogoba]

Hi everyone!
Anyone knows how to get the reduced stiffness matrix in abaqus?
I know how to get the global one.
After the STEP1,

*STEP, name=exportmatrix
*MATRIX GENERATE, STIFFNESS
*MATRIX OUTPUT, STIFFNESS, FORMAMT=MATRIX INPUT
*END STEP
**

But i need to reduce the model. I don´t know if i have to do a substructure or what.

Thanks in advance!