How do I add a video to a score?

Mar 28, 2018

I want to add a video to a "Trick or Threat" background music score of me singing the lyrics, but I don't know how that works. I HAVE seen it before, so I know that it's possible, but I just need a how so I can finish this why.
Also, for some people, when I'm finished, I need you guys to tell me which of my scores is the worst so I can get rid of that one. (cuz i'm not a pro and don't plan to be)