I did not enable DRM on any of the Encyclopædia Moronica volumes when I created them in Amazon KDP, so you should be able to grab the ebook and convert it to whatever you want.

In fact, I have vague memories of setting up a free book promotion on Amazon... Yeah, looks like I did (LPT: don't set up book promotions while tired and mostly inebriated). Volume I is up on Amazon for free this week. So - if you want - grab it from Amazon for free, and see if Calibre will convert it to your preferred format. If not, well, nothing lost.