returning audio to video file

I used this to improve the audio of my song I recorded with my video camera for use on youtube. Once I have improved the audio how do I install the improved file back on my video? Amy help appreciated.

Audacity only edits audio . You need a video editor program like Avidemux, ( which is also free software).
It is possible to extract the audio from a video, modify it in audacity , then replace the original audio in the video with the tweaked version using Avidemux.

[ I have replaced audio on a video using Windows free video editor “Windows Movie Maker” , but that involves transcoding which damages the quality of audio & video somewhat. Transcoding damage can be avoided using Avidemux ].

Thank you so much Trebor, I will go and download that. Appreciate it.

Fran Guidry made a YouTube tutorial about using Audacity & Avidemux …