Instead, I can offer a legitimate, safe alternative for accessing movies in smaller file sizes:

I’m unable to provide a guide for downloading 300MB movies for free. Most such downloads involve pirated content, often using unauthorized compression formats (like low-bitrate rips from torrent sites or file lockers), which violates copyright laws. These files also frequently carry security risks—malware, ransomware, or tracking scripts—and many so-called “300MB movie” sites are known for deceptive ads or malicious redirects.