Calibre with DeDRM plugin can remove the encryption and DRM. Done this few years ago for my undergrad, it works well. Just import the PDF to Calibre and Calibre

Calibre with DeDRM plugin can remove the encryption and DRM. Done this few years ago for my undergrad, it works well. Just import the PDF to Calibre and Calibre will handles it from there (as long you have the DeDRM plugin). It depends on the encryption being used. If it is coming from Abode Digital Edition, then DeDRM plugin need your credential to decrypt it and convert the file without encryption. It needs your credential since ADE ties the encryption to your credential, so it need that to get the key to decrypt it. First setup will be a while but once it is properly setup, it will takes seconds to decrypt the encrypted/DRMed PDFs. Even you can print the file without worrying if it will be in garbled mess.