To use this Chelsea FC musical birthday card, simply open it up, and the music will start playing automatically. It's a great way to surprise the birthday person. When handling the card, be gentle to avoid any damage to the crest or the graphic inside. Store it in a dry place to keep it in good condition. If you want to reuse the card, you can close it carefully and it'll be ready for the next time. Just remember not to expose it to water or extreme heat, as this could affect the music player and the overall quality of the card.