Thanks for using Apple Support Communities.
For more information on this, take a look at:
How to delete content you've downloaded from the iTunes Store, App Store, iBooks Store, or Mac App Store
Open the section below for the device you are using.
Before you delete, find out if you'll be able to download the song you deleted again (it depends on where you live). To delete a song:
- Tap the Music app.
- Tap the Songs category.
- Swipe left to right over the song you want to delete.
- Tap Delete.
Best of luck,
you can use iFile with this steps :
1- open iFunBox2
2- go to ( Row File System )
3- open folder named ( Purchases )
4- scroll down to find the ring file to delete it
5- you can download iFunBox2 from : http://dl.i-funbox.com/
if this link did not work you can go to this page to get it : http://www.i-funbox.com/