Several things can break on a riding mower. Anything from the tires to the fuel tank may need replacement during a riding mower's lifespan. Though many repairs require specialized tools, at least one does not -- replacing the fuel tank. It's a job the average homeowner can handle.
Locate the fuel tank. Some mowers have the fuel tank under the hood by the engine, while other locate the fuel tank under the operator's seat.
Locate the retaining screws on the fuel tank. Most riding mowers have four mounting screws on the tank, two on the top and to on the bottom. Some mowers require a socket and ratchet to remove the tank.
Locate the fuel line connection at the bottom of the tank.
Place the bucket under the connection. On some mowers the fuel line must be removed from the engine to properly drain the tank.
Remove the fuel line from the tank. Squeeze the clamp and slide it away from the tank, then pull the fuel line off the barb on the bottom of the tank. Allow the fuel tank to drain. Removing the fuel cap will make this go faster.
Remove the mounting screws on the fuel tank with a screwdriver. Some mowers require a socket and ratchet to remove the tank mounts. Others require the entire seat assembly to be removed first. Double-check the owner's manual for the proper procedure.
Install the new tank in the proper location. Make sure to install all the mounting screws.
Install the fuel line on the barb on the bottom of the tank. Press the fuel line on the barb, then squeeze the clamp with the pliers and slide the clamp back over the fuel barb.
Fill the tank and check for leaks.