How to export audio from the recorded video using Replay?

Interesting that Articulate always questions the use case for obviously needed functionality.  My use case is recording a screencam using a headset.  With a headset recording you always need to clean up the audio background, but there is no such feature in Replay. I have a 43-minute screencam, where the flow is:

1.  Save replay file (4 minutes)

2. Publish to mp4 (25 minutes).

3.  Open mp4 in Wavepad and clean up the audio (auto spectral subtraction).  Save as mp3. (1 minute total)

4. As suggested by others, mute audio on trackA and import audio on trackB. (1 minute). 

5.  Save replay again (4 minutes)

6. Publish mp4 again (25 minutes)

So the benefit of including audio cleanup in Replay is 29 minutes (eliminate steps 5 and 6).  Alternatively they could make better use of PC resources to speed up the Publish function.