I've used Audacity to tinker with the audio and have that saved, looks like I just need a way of removing the original audio from the mp4 and adding in the saved audio.
Many thanks for all the suggestions, will have a look at them tonight.
I've used Audacity to tinker with the audio and have that saved, looks like I just need a way of removing the original audio from the mp4 and adding in the saved audio.
Many thanks for all the suggestions, will have a look at them tonight.