Audio Where To Begin With Editing In Train Announcements?

I can't be the only one slightly annoyed that the in train announcements on the Medway Valley Line are not read by Julie Berry. The audio files are available, but I am assuming its not a case of swapping them out either. Where would I start with it? I play with audio - I have a background in sound engineering. I also program a bit so I think I could give it a go.