Is there an easy way to relink original audio with a video clip?

I have recently been working on a video and have replaced the original audio of each video clip with that of an external recorder, unfortunately (and due to me being stupid) I've only now realised just to bad settings on the audio recorder that the original audio recorded with the video is much better quality.

Is there a way to relink this audio to the original video file? I am using CS6, thanks

Dan