I found two articles that can help you out. The first one goes over converting the ID3 tags, while the second one talks about manually modifying information about songs:
I've tried converting the ID3 tags, and the songs titles appear scrambled (now with presents of some of the characters that looked chineese). Couldn't reverse the Unicode either. Manual songs info modification would work if I knew correct songs titles (either in Russian or English characters) which I have no clue. So there is still no solution. But thanks for your help anyway. Cheers.