You can submit a request online to change the power of your meter. The cost varies according to the power requested. 

In addition, you will need to have the electrical panel in your home adapted to distribute the phases appropriately. 

NB: having more power also involves a tariff cost. Today, it is still limited to a surplus of about EUR 30 per year if you exceed 13 kVA. But the pricing of electric consumption will surely evolve towards pricing based upon capacity. You will therefore have to pay more if you need more power.