see on GitHub

Attachments: Deleting Attachments

Delete from session.advanced().attachments() is used to remove an attachment from a document.

Syntax

void delete(String documentId, String name);

void delete(Object entity, String name);

Example

try (IDocumentSession session = store.openSession()) {
    Album album = session.load(Album.class, "albums/1");
    session.advanced().attachments().delete(album, "001.jpg");
    session.advanced().attachments().delete("albums/1", "002.jpg");

    session.saveChanges();
}