If the listing is yours, you will need to claim it on Trulia so that you can edit the listing information. Access the link below to access the My Listings section of your account and search for the listing in question. Once you've claimed it, you should see the option to edit it on the very same page and you should have no problem updating the address.
Let us know if you need any additional help. You can always feel free to contact our Customer Service team directly - either by phone at 888-466-3501 Monday - Friday 7am to 4pm PST, or by email via the link below.