How do I file a motion to modify a recommendation that the Friend of the Court referree made?

I live in Oakland County Michigan and last month we had a Child Support Review at my ex's request. I was unable to attend because my child and I had H1N1. Since I was not there my income was imputed at 30 hours per week and 7.40 an hour. I am currently not employed so does anyone know the proper steps to take to file a motion to fix it or even what the motion is called? Thanks in advance!!