My Craftsman rider model 917 has a 6 speed and 19 HP. No brakes and no parking brake. How do I troubleshoot and repair?

Look underneath to see if a linkage rod has fallen off. Then check to see if the two small pins on the side of the trans by the brake move when someone else pushes the brake pedal.

My Craftsman rider model 917 has a 6 speed and 19 HP. No brakes and no parking brake. How do I troubleshoot and repair?
Model 917. What? Not the complete model number.