P0745 Hyundai - 2000 hyundia tiburon wont shift gears what is the problem

Question

Car struggles to shift gears I've already changed transmission oil and filter found little pieces of metal on magnets on oil pan have a feeling something broke but I'm no sure because their very little pieces took transmission valve off to see if any problems could be seen but none spotted don't know if I put the valve back together correctly so I need a diagram of its reassembly