FIR multi channel and reload coefficient

hello,

I use the FIR filter described here http://www.altera.com/support/examples/nios2/exm-accelerated-fir.html. I need to change the design to change the coefficient by the Nios II. In this design the coeffcient are initialized in the HDL code by "assign coefficients = '{ `include "coefs.h" };"

Please how can i change the filter coefficient from the Nios.

Thank you.