Three steps: settings, import the films, fetch the posters. You only do this once.
Re-running this refreshes titles and ranks. It matches on IMDb ID, so your votes and comments survive.
Looks each film up on TMDb by its IMDb ID (exact match, no guessing) and caches the artwork on your own server. Runs in batches so it never trips a PHP timeout. Roughly 30–60 seconds for all 250.
Save this. It is the only way back into this page once the site is live.
(saved on first install)