To use this 2-in-1 DIY kit, first choose whether you want to build the steam robot or the steam train. Follow the instructions in the box to assemble it using the pistons and rods provided. Once it's built, add some water to the chimney. This will activate the Ultrasonic Atomiser, which will create a mist and start the engines. The LED light on the chimney will flash like a flame, adding to the fun. Remember, this product is for kids aged 8 and above. Keep it away from small children to avoid any choking hazards. After use, make sure to dry the chimney and other parts to prevent rust. Store it in a dry place when not in use.