Convert an audiobook .aax to .m4b using ffmpeg

brew install chromedriver ffmpeg
sudo easy_install pip
pip install selenium requests
git clone
cd audible-activator
sed -i '' 's,chromedriver_path = "./chromedriver",chromedriver_path = "/usr/local/bin/chromedriver",'

When running It will ask for the audible username/password it will open chrome, and when finish print the activation bytes:

$ ./
Username: your@email
[*] Player ID is 1xmjyl5rSw0yVb/olWBYuU/NBxk=
activation_bytes: b97f4709

One having the activation_bytes, use ffmpeg:

ffmpeg -activation_bytes b97f4709 -i input.aax -vn -c:a copy output.m4a;mv output.m4{a,b}

More info: