how do you download an outside ringtone

How to Buy / Download Ringtones from App Store

1. Open the iTunes Store app.
2. Tap  More.
3. Tap Tones. 
4. Find a ringtone that you want to buy, then tap the price.
5. Choose an option to automatically set the ringtone. Or tap Done to decide later.

Search for 'ringtone' in the App Store. You will find several apps that can reformat and install ringtones from your source music.

The process that these apps use takes three steps. First, your music is edited down to 30 seconds for a ringtone or 8 seconds for an alert tone. Then the software converts the music to MP4 format and renames the extension to .m4r for ringtones or .m4a for alert tones. Lastly, it installs the tone on your Apple device.

Good luck.