If you are unable to access your account and need to reset your password, use the password reset page and enter your email. You will receive an email with a link to change your password.
If you already know your password and wish to change it, you can do so on the account settings page.
On the account settings page you can change your password by typing your current password into the "current password" field and then the new password into "password" and "confirm password".
When you are finished, click update details. Your password has been updated!