Lower the temperature.
The reaction is exothermic.
That means it can also be shown as:
If temperature is lowered in the system, the equilibrium will favor the products. Because the energy is on the product side in an exothermic reaction, if energy is removed, it will return again to the product side.
If temperature is increased in the system, the equilibrium will favor the reactants. If the energy that already exists in abundance on the product side is added to, the system will shift to the right in attempt to "equalize" the imbalance caused.
Thus, to maximize