Answer is: by increasing the temperature of the solvent.
Saturated solution contains the maximum concentration of a solute dissolved in the solvent (usually water) and if extra solute is add to saturated solution, that solute will not dissolve.
The amount of solute that can be dissolved in a solvent depends of chemical composition, temperature and pressure.
In this example, because chemical compostion and pressure are the same, the amount of solute that can be dissolved in a solvent depends on temperature.
The higher the temperature of the solvent, the more solute will be dissolved.
