how to download all videos from a user on youtube or extract music from every video

how to download an entire youtube list of videos from one user

or 

how to extract audio from an entire video collection of one youtube user

download freemake video downloader

then go to the youtube user profile and click on "VIDEOS", copy that link

example
https://www.youtube.com/user/nvidia/videos

paste that link in freemake video downloader "PASTE URL"

wait a little while it loads, then select the videos you want or all, etc

if you want videos, then select quality and ONLY DOWNLOAD

OR

if you want just audio select : ORIGINAL AUDIO


then download

that is all

very easy