Hello,
I would be happy to do this for you. I don't think you realize how audio software work.... it doesn't matter if it is a short clip or the entire length, the amount of work is the same. I previewed the interview and it needs to be mastered and normalized. Currently, the audio volume is low compared to the ambient noise. It is a difficult job to clean up audio but not impossible. There will still be some hiss regardless but it will be more audible. The job will be easier if you could provide a WAV sample which is not compressed audio also.
I can make the flow of the interview sound a little better and not so choppy in terms of talk flow too. So once I set up and work out where the ambient hiss is happening i will attempt to cut it out or treat it and then boost the audio and clean up any problems with the talk flow and glitches. The majority of the work is with removing the right frequencies and that step is the same for treating the entire audio or a small sample.
I am pretty sure I can tackle it within a day. Please note, audio is the same as graphics, once the quality is degraded, its hard to undo, but can be improved, so it wont be a complete removal but a better version.
Looking forward to hearing from you.