First, you'll need to download the audio file below:
(if you are using your phone, please manually save to Dropbox)

Once you've done that, you will want to make sure the file is saved to either your iCloud or Dropbox Drive.
Then you need to download the free app Garage Band, and follow the instructions below:

You will then be able to save the file and set it as either your ring tone or message tone.
However, note that this works as your normal iMessage alert ONLY. Unfortunately we won't be able to get saved on WhatsApp.