How to make Ed-E's floating sound quieter?

[bitbop]

I know like nothing about modding, but if you point me in the right direction I'm sure I can figure it out. I'd just like to make Ed-E's floating sound much quieter. I know how to lower the volume if I get the Wav, I just have no idea where the file is or how to unpack it from wherever it is and pack it back into the main sound pack.

 

Thanks for any help.