Audible files are in .AAX format (encrypted). You can use the free software "Libation" to convert your legally purchased Audible books to MP3, but converting trial books is technically against terms of service.
series ( A Song of Ice and Fire ) requires navigating between legitimate library services and limited-time promotional offers. Since the series is under copyright, it is not legally available on public domain sites like Project Gutenberg or LibriVox .
Major audiobook retailers offer free trials that include one or two permanent credits, allowing you to keep the book even after the trial ends.
If you are transitioning from the HBO show to the books, be prepared: