I've done them on my own, same with VHS tapes. Today I saw an add for a device that you pop the cassette into and it outputs mp3 to your computer, but I think you want a more robust file than mp3 as far as stereo, quality, etc. I just scrolled back through my Instagram - it's called the Mini USB Audio Cassette Tape Converter. The site is casettetomp3.com.