Listing agents can still manage photos on closed listings by going Listings on the top navigation bar and then Maintain Listings.
From the listing maintenance grid, click the Select an Action option.
Then select Picture Administration on the popup menu.
Check the boxes of the photos you'd like to remove and then click the Delete button on the toolbar.
Please note: A minimum of 3 photos would need to remain on the listing to be TMLS compliant. Changes made to a Closed listing will sync with 3rd party sites (Realtor.com, Zillow, Trulia, etc.) that utilize IDX feeds, however, you may need to reach out to any 3rd party site if the closed listing does not update.