I looked up the instructions for Dvorak on https://support.apple.com/kb/PH21495, but they do not seem to apply to my case, as they only list a way to select the Dvorak layout, and not a way to install and select the Programmer Dvorak layout.
I also followed the variations of the instructions related to Mac OSX Mavericks at the following link, to no avail:
After installing the layout driver package and following the instructions for "Adding Programmer Dvorak to the list of available layouts", even after a restart of the OS, and clearing of the layout cache by
sudo rm -f /System/Library/Caches/com.apple.IntlDataCache.le* no Programmer Dvorak layout appeared.
I installed Mr. Kaufmann's package successfully, but it did not seem to change any of the listed keyboards.
Neither a search for "Dvorak" nor a search for "Programmer" gave me any good results for the Programmer Dvorak keyboard layout.
I can put screenshots, here, too, but I do not want to make this question too specific to my particular setup, as this is a general interest question and answer site.
I welcome specific answers as well as the usual steps for troubleshooting Programmer Dvorak Keyboard Layout installation on El Capitan.
Regardless, how do I set up Programmer Dvorak Keyboard Layout on El Capitan?