The toilet tank mechanism was fully replaced, including the fill valve, flush tower, tank-to-bowl bolts, and all required gaskets. The tank was properly reassembled and securely mounted to the bowl, ensuring correct alignment and a watertight seal. After installation, the system was thoroughly tested for proper filling, flushing, and shutoff operation. All components are functioning as intended, and no leaks were observed at the tank, bolts, or supply connection.