As it turns out they don't actually want you to do this (and have some interesting ways to stop you)
TL;DR
I bought my first ebook from amazon
Amazon's Kindle Android app was really buggy and crashed a bunch
Tried to download my book to use with a functioning reader app
Realized Amazon no longer lets you do that
Decided to reverse engineer their DRM system out of spite
Discovered multiple layers of protection including randomized alphabets
Defeated all of them with font matching wizardry
You can now download the books you own books with my code
... continue reading