You can change your password here in your Account Settings.
Here's how:
Go to your Account Settings. It's on the bottom left side.
Scroll down to Password, right after Portrait.
Enter your current password and then enter a new one below. Click "Save" to start using your new password immediately.
I forgot my password! What should I do?
If you don't know your current password, please click on "Forgot your password? Reset it" on the lower left side and enter your email on the next screen. We'll email you the information you need to reset your password.