If you have used WikiTree before, you should still be able to login using the same e-mail address and password you used in the past.
If you don't know your password, you can have one e-mailed to you from a button on the login page.
If you don't have access to your old e-mail account, you'll need to contact us at info@. Be sure to give the ID/URL of your account page, and let us know something that will enable us to verify that you are who you say you are, i.e. so we really know it's your account.