QUESTION: How can I remember past lives and prove they are real?
ANSWER: Your belief is your only proof. If you believe enough, any evidence will be proof. If you don't believe, no amount of evidence will be proof enough. The easy way out is to believe in them when it is helpful to do so, and don't believe in them when it isn't.
Assuming they are real, look at places and cultures that interest you greatly, languages you learn easily, and talents you have that your family doesn't share. Studying these can trigger memories. Also, try dream recall, guided meditation, hypnosis, and self hypnosis.