How to make a video public on facebook?

[pri✍]

I don't understand, if it's you own video, either you can set the audience to Public when you upload it to FB, or you can change it later to Public, just click the audience selector & tick Public.
What are you talking about, where you upload that video?
If it's your own video, you also can email it directly to that person, or upload directly in your FB message to that person if that person also in FB even not your FB friend.
The last confusion is, if that is your own video, why do you need to download it from FB? Public or not, you can download a video from FB if you have the tool to do it.