To delete one of two videos

I am making the audio for a video project and I have added the new edit of the video in the project, and now I have two videos in the same project. I would like to delete the older video but when I try to do it, it also remove all the added audio that seems attached to it (this audio has been added manually and is not part of this video file) - please find a screenshot of my project, I would like to delete the second bottom video . Any idea how I can delete this older video version and still keeping the added audio? It seems that this audio attached itself to this older version. Thank you.