This sounds made up.
I purchased a song on iTunes a long time ago, during the time that an Apple ID was required to unlock access to the file. I lost access to the associated email address and Apple ID password. I don’t want to steal a song that I morally own. How do I unlock the file without the Apple ID password?
For what its worth to OP you might want to look at what laws apply in your area. Many countries may indeed be okay with you downloading a song you already own (as per transiet punk) BUT be against you breaking copyright protection (decrypting it).