Navigate to the folder you wish to download the file from Dropbox link. If your computer appends .txt to the end of the file, simply delete .txt and it should then work fine. Alternatively use the Chrome browser instead)
Please note that these are saved in TCX format, and will work on current Garmin units and give turn by turn directions. If you have an older Garmin or a different GPS Satnav you can download the files and then convert the files into GPS format at this site.
The rides are now also saved as .png (graphic) files so they can easily be viewed prior to downloading.