If the video is lower quality because you were new and didn't really know what you were doing (*cough* like most of my old videos *cough*) and you just want to cover some of the same information in a better way, then just recreate the video and make it better than the original.
If the old video is great as is and simply didn't get many views - then create a new video on the subject but perhaps not covering the exact same thing, and direct people to your older video in there. You kill two birds with one stone: 1) you get people to visit the old video, and 2) you're extending your viewer's watch session by getting them to watch 2+ videos in a row, which will make the algorithm favour you.