Headline. Massive block letters at the top of the article. Front-page notice. Put retractions and changes front and center. Make it clear that that's part and parcel of the process of reporting and journalism - that not all mistakes, intentional or otherwise, can be prevented, but that they can at least be corrected transparently. Without that, there is even less reason to trust that their intentions will lead to accurate reporting.
The latter is a propaganda outlet. Places like WP may not print retractions quite like you'd like, but they do print them, people do get fired for ginning up stories, and there is a sense of accountability.