Remove the locknut (A) and the fuel tank unit assembly.
Install the parts in the reverse order of removal with a new base gasket (B) and new locknut, then check these items:
When installing the fuel gauge sending unit, make sure the connection is secure and the connector is firmly locked into place. Be careful not to bend or twist it excessively.
When installing the fuel tank unit assembly align, the mark on the fuel tank (C) and the fuel tank unit (D).