Decrypt a book

I bought a PDF book but it is custom encrypted and will only let me see it with Adobe Digital Editions by opening the acsm file. I tried many things to decrypt it but didn't work. I need to be able to edit the book for my own entertainment so I need someone to decrypt the PDF file completely. I don't really care if you recreate the PDF by merging snapshots as long as it's the exact same book and I can edit the words (like you would with a word processor) and I can save the file.