how to destroy an object then instantiate another from a prefab

I've got an object called board_new that was made from a prefab with the same name. I want to destroy the current instance and then instantiate another at a new location. Can somebody tell me how this is done? There will only be one board_new instance at any given time.

Thanks

Destroy(instance);
instance = Instantiate(prefab, newPos, newRot);