Is there a way to easily use music from Google Play Music as ringtones on my phone?
Download the song and use something like Audacity to edit it. Save to your ringtones directory on your phone. Nothing else out of the ordinary needs to be done.
download the song on another device
then use makeownringtone.com to cut the ringtone and download it
then move the ringtone to dropbox
then on the phone export the ringtone from dropbox to the Ringtones folder