Stir Together The Apple, Pecans, Salad Dressing, And Sour Cream; Set Aside. Place A Slice Of Colby Cheese Onto 4 Of The Bread Slices, The Add The Ham, Followed By The Remaining Slice Of Cheese And Bread. Spread The Margarine On The Outside Of The Sandwiches. Place The Sandwiches Into A Large Skillet And Cook Over Medium-High Heat Until The Bread Is Golden Brown On Both Sides And The Cheese Has Melted, About 3 Minutes Per Side. Spread The Apple Mixture Into The Middle Of Each Sandwich Before Serving.