It is quite simple to use Y2mate for Youtube video playlist to Mp3 converter or Mp4 downloader, especially so if you're on a desktop or laptop computer. This process will work on mobile devices, just keep in mind not to use up your monthly data in 1 shot. First we need playlist URL same as video URL, and after it's just clicking on whatever videos you like to download or convert. Here's detailed instructions:
Copy playlist URL from Youtube, it is easy to do so using Share menu or from the browser address bar.
Visit y2mate and insert Yt playlist URL into input form, hit Download button, wait for the list of videos to show up.
Now click on a video you like to download or convert, and do so using the options menu.
Finally, repeat step 3 for all the videos you're interested in.