The method is easy.

by R. Proffitt Moderator - 1/28/13 10:03 AM

In Reply to: How to put audio files on AVI or FLV files by richardmp

You pull it up in your video editor (natch!) and then use your mic to record your voiceover as it plays. Then in the video editor drop in the audio track you needed where you want.

This is not an offer to detail how to use or select a video editor.
Bob