IDML contains quite a few XML files, but I suspect you're only interested in the Stories folder if you're working on a translation. The way to do that is... to reduce the number of stories. If it's a two-pager, chances are that you have a whole bunch of unthreaded text frames. Thread them in logical reading order. This will help the translator(s) as well - by threading frames in logical reading order, they don't have to work to read the document in the same order as the target audience.