Hi,
If you only have a few listings to update, I’d recommend updating the photos manually. Just select new photos for each listing one by one.
If you’ve got a bunch to update, you can use our Import plugin to do them all at once. Just make sure your photos are set up as URLs with commas between them.
Another option is uploading all the images to WordPress/Media and modify attachments in the database, settings the corresponding listing IDs in post_parent field, and meta fields as described here Listing images are not showing in admin uploaded with custom coding - #7 by ihor
Hope this helps