This is only going to help a few people, but if you're still on one of the older kindles, such as the old original kindle paperwhite, when you ask for the file,

This is only going to help a few people, but if you're still on one of the older kindles, such as the old original kindle paperwhite, when you ask for the file, you can request it for these older devices, and the book format will have the old DRM which can easily be stripped.