How to convert 4x4x1 layer to 6x6x1 layer?

I calculated a Zn-doped graphene 4x4x1 layer. I need to create a 6x6x1 layer with an equilibrium distribution of Zn on the surface. How can I do it in the Material Studio Platform? Could you please assist or suggest me in this respect?

With advance thanks and appreciation for the suggestions.