Well, normally I never answer my cellphone, it's always Virgin wanting me to go to a kiddie concert. Recently, I had a need to answer the phone, and the ringtones are all ugly.
So, you get a nice song - buy it, yeah. And you fire up Audacity. No need to read any instructions, just fumble along like I did. Eventually, you stumble on how to do a selection, then copy it and paste it into a new project. Maybe do it again, like I did.
You can export this to an mp3 file, and put it on one of your Samba shared folders. Then on Android, use ES File Explorer, and copy that file down to Ringtones. Select it on settings. That's all!