iPod MC692

How can I dissasambly iPod MC692? It's power button doesn't work. If I connect this to charger or PC via cable, it'll work. Else: I can listen music until it's screen turn off. In fact I must listen music longly when it's battery is low! What I do?

I'm waiting for your answers. You can send me letter my email - zohidjon.net@gmail.com