Remove DRM from ePub Files?

I have a bunch of ePub files that I have bought from Barnes & Noble that I'd like to be able to read in my Kindle App. Is there anyway to do this?

UPDATE for those who are lecturing me on the law and morality:

Simply breaking DRM is not illegal in the US according to 5th Circut Court of Appeals (see this article for a quicker analysis). Basically it's legal to remove DRM on your own files as long as you don't then use them to violate the copyright. Even if you disagree with the decision, at the very least it's debatable, not illegal.

I do not download pirated music or movies. I don't pirate software. I don't even use a copy of software that a friend "lends" to me.

I purchased these books (originally as pdb files) to be used with eReader for Android (when it still worked). Later, when B&N released the Nook App, they deleted my .pdb files and replaced them with ePub files that only worked with their App, which is terrible compared to the Kindle App. I wouldn't have purchased them if I knew they'd do this. Were they within their rights? I don't know but probably. Honestly, I don't care, I just want to read my books. I have no intention of violating the rights owner's copyright.

Solution 1:

Some guy with a blog called "I♥CABBAGES" seems to have reverse engineered ePub DRM, and some other guy wrote a detailed How-To guide here:

Free epubs from Adobe ADEPT DRM

Which refer to scripts you can find here:

Circumventing Adobe ADEPT DRM for EPUB

Note: If you get the error: "Not an ADEPT EPUB", then your ePub file is missing the META-INF/rights.xml file in its archive because it probably wasn't downloaded from the publisher correctly. Here's how to resolve the issue:

1. Re-download the book from the store you bought the book from and observe that you just get a .acsm file instead of a .epub file.
2. Instead of inspecting the contents of this .acsm file to get a link to a .epub file, you will have to open the .acsm file in Adobe's "Digital Editions" software (which is a horrendous piece of crap, by the way).
3. After opening the .acsm file, Digital Editions will put a working .epub file in My Documents/My Digital Editions on Windows. It probably does something equivalent in MacOS, use your intuition to figure out where it might put the file.
4. Run the scripts mentioned on the Circumventing Adobe ADEPT DRM for EPUB page on this .epub file.

There is also a method specific to Barnes & Noble:

Circumventing Barnes & Noble DRM for EPUB

Solution 2:

There is a blog post with tools that worked for me:

DRM Removal Tools for eBooks

It has updates to original tool from "I♥CABBAGES" and also plugis to Calibre.