Hello, I am attempting to remove the instrumentals from a video soundtrack (.mov). I understnd the process of lining up, inverting etc. Will I then get a video with just the vocals on it? What I am really trying to do is to take a video of a singer and make it an acapella (sp.). I am new at this and visually challenged so this will take a bit of patience. Any assistance is appreciated. 
I am using a Mac.
That’s important for any detailed instructions, so topic moved to Mac forum.
and do you understand that the process usually does not work?
Not from Audacity. Audacity works only with audio. If you import a video file (requires that you have FFmpeg installed), then only the audio part of the file is read.