Unplug the power cord from the electrical outlet to prevent it from accidentally starting.
Pull the cover off the top of the processor and slide the disc stem onto the power shaft in the middle of the processor.
Line the hole of the shred disc over the metal pin of the disc stem and slide it onto the pin. Turn the disc repeatedly until the disc falls fully onto the disc stem.
Replace the cover of the food processor, plug the power cord into the electrical outlet and turn on the power.
Insert food into the feeding tube and push it evenly with the food pusher. The shred disc will shred the food.