First step: Check the legality. In many countries, downloading Bluray movies without proper permission is illegal. I should start by advising them to consider legal options. Maybe services like Amazon Prime, Netflix, or YouTube have Bluray quality options. Need to list those.

If they insist on unofficial methods (which I shouldn't recommend), maybe suggest torrenting sites, but again, I have to be cautious because promoting piracy is against policies. Maybe just mention that it's important to respect copyright laws.

Need to structure this in a clear step-by-step guide, but first address legality, then possible sources (legal), then technical steps if they choose to proceed, and finally alternatives. Make sure to mention that while I can't support illegal activities, I can provide information on legitimate ways to obtain the movie in high quality.

But the user might be in a country where legal access is limited, so maybe balance by first promoting legal methods, then noting alternatives, but not endorsing piracy. Also, emphasize the risks of downloading from illegal sites: malware, bad files, legal consequences.

Device compatibility: Not all devices can play Bluray discs natively. If they're downloading a digital copy, they need a compatible media player. Software like VLC or hardware like a 4K TV with Bluray support.