I'm sorry that no one from Trulia answered your question previously. If you manually submitted the listing information to Trulia you can update those listing details within the My Listings section of your My Trulia account.
If you did not manually submit the listing information to us then access your listing on Trulia and follow the link to view additional property details and photos. There you'll find the site that sends your listing information to us. You will need to make sure that the listing information is updated on this site and Trulia's display will then update automatically with the new information. If however you find that the information on this site is correct and Trulia's display is not, please click on the 'Report listing error' link next to the red flag to report this problem to us.
Also, at this time co-listing agents can both claim their listing so that it will show up in each of their My Trulia accounts, however only the photo for the first agent will show up on the listing details page.
Customer Service Representative