Using your Mini Hornit LIDs kids helmet is easy. First, adjust the straps to fit your child's head snugly but comfortably. Make sure the helmet sits level on the head and covers the forehead. To turn on the LED light, just press the button on the side of the helmet. You can cycle through the 3 light modes with each press. When it comes to battery replacement, open the battery compartment and swap out the 2x AG3 cell batteries when they run out. For maintenance, clean the helmet with a mild soap and water solution. Don't use harsh chemicals as they might damage the helmet. Also, store the helmet in a cool, dry place when not in use. And always check the helmet for any signs of damage before each use. If it's been in an accident, replace it right away for your child's safety.