To instantiate view need to call thread-safe method world.InstantiateView(viewId, entity). Short method is entity.InstantiateView(viewId).
You can attach only one view on each entity at once. If you try to Instantiate second view on entity which already has view component, you'll got an exception. If you want to change view on entity - use entity.DestroyAllViews(); before calling InstantiateView.
entity.InstantiateView(this.viewSourceId);
or
this.world.InstantiateView(this.viewSourceId, entity);