Well, first of all, take it to someone who knows what they are doing. Cracks are always structural issues, and doing it wrong is a sure way to have your guitar fall apart.
But even so, without knowing where the cracks are, or how they happened, I couldn't tell you how to fix it even IF it was a good idea for you to do it yourself.
Light
"Cowards can never be moral."
M.K. Gandhi