Necchi Sewing Machine Model No. 50910225T instructions?

I have this sewing machine model and am unable to attach the pressure foot to the machine in order to sew. It has a special 'foot' that is in 2 pieces and one must fit into the stem and snap shut but I am unable to attach it and without the foot installed the machine is worthless. There are NO INSTRUCTION MANUALS WITH IT and I have been unable to get any help on line from the Sewing Machine company importers who sell it in the U.S. Desperate!