Extract the ZIP files (at least the CoreDOcs zip, with the other zips being optional) into one main folder. The cleanest way is to first create a folder, then open each zip and extract its contents into this created folder. The results would be this main folder with over 40 files and two subfolders (font & images), the three optional folders will each add their own subfolder (VacD-Pages, Tutor & Chants), making a total of two to five subfolders in this one main folder.

In the main folder select and open "AKA-index.htm" or "_Start.htm". This should open in your browser. If not, then open this file with your prefered browswer (Chrome, Edge, Safari, etc.) by dragging either of these two files onto the address line of the browser. In the opened AKA-index page you can select any of these many documents, including the dictionaries, from within this page.

If you do not have a good Devanagari font, in the font subfolder there is a gorgeous Siddhanta1.ttf true-type font that can be installed into your computer. Usually, by just opening the Siddhanta1.ttf file, your computer will recognize it as a font file to be installed and provide an option to install it.

Enjoy,
-AK Aruna