I have duplicates of albums on Play Music, one without art or an artist

[AC Question]

I tried adding music to my Samsung s4 by dropping the iTunes files into a music folder that play music reads from. Unfortunately, at times play music can't read the album art or artist name. I plug my phone back into my PC, delete the files and try again, this time converting the file before hand (I'm assuming to an mp3 or wav or something) this time it works perfectly fine, but even though there is only evidence of one copy of this music on my devices storage, there are duplicates within play music. How do I remove these duplicates manually within play music?