Welcome to Trulia Voices and thank you for your question. It's actually very easy to claim a listing that has already been added to our site. Just access the link below to navigate to the My Listings section of your account. There you should find a search box that will allow you to search for the listing by address or using your email address. Once you find the listing in question you'll then be prompted to claim it so that it displays your contact information and so that you can keep track of this listing from the My Listings section of your account.
I hope this helps you. Please let us know if you experience any difficulties with this process or if you have any other questions or feedback for us.