Other instructions were a bit hard to follow, so here are some easier ones:

Open the file in audacity, click "edit" and select all

Then go to "effect", "change pitch", and in "Frequency (hz)" Put this:

440 to 432

Don't worry about changing what's already there (like if it says something other than 440), this will do the trick fine. It should say "percent change: -1.8"

There you go, enjoy!