The last I looked into it, the best way to do it was to get an older kindle so you could download the older DRM copies of books from amazon. But I think some newer books are using only the newer DRM which I don't think has been cracked.
It has probably been at least a year since I checked. If you do end up finding an updated method, I would be interested.
A ton of people using github barely understand the different between github and git and often think they are the same thing or that github and git are somewhat related more than they really are.