I bought an audio book for my vision impaired wife to play on her Book Port Plus via the USB port. It was downloaded on my MAC computer with ".aa" subscript in iTunes but I need software to transfer the files. Could you please help?
There is software available for your product on the official website. It doesn't matter if you have Windows or Mac as there are 2 versions of the software, each for one of the environments. Install the application, then connect the device using the USB cable and transfer all the files needed.