Using this toy is super easy! First, push the engine along to play with it just like a regular toy train. To see the color - changing magic, simply put the engine in water. You can change the water temperature from warm to cold and vice versa to reveal the hidden decorations. Remember, each engine is sold separately, so if you want more characters, you'll need to buy them individually. Also, check the availability before you make your purchase. When it comes to maintenance, just rinse the engine with clean water after playing and dry it with a soft cloth. This will help keep it in good condition for a long time.