Hi Olivia,

As far as we are aware, the mph speedo in that car also has km/h markings on it, so we'd suggest it's not worth the cost of changing it over.

If you really do want to get it changed, I suggest you bring the car to a Nissan dealer first and foremost, as they'll advise you on the parts that are needed and the likely cost. In some cars it's possible just to change the face of the dial, but it's still a considerable amount of work to take the dashboard apart to do that.