How to transfer ringtone to computer

I have a Macbook Air OS Yosimite 10.10.3 and want to transfer a customized ringtone (a clipped song) from my iphone 4 to my Macbook Air, in hopes that I can convert the ringtone to an M4R and transfer it to my new iphone 5.

I have followed the directions to sync my iphone to iTunes; however, the song only shows up in itunes when my iphone 4 is plugged in. When i plug in my iphone 5, the song is not saved in iTunes for me to convert and transfer it. When my iphone 4 is plugged in, I've tried dragging the song from iTunes to my desktop so I can convert it and it won't let me. There is no "save as" button to save the file to my Mac.

How the heck do I copy the ringtone to my computer? I have also tried to access the ringtone on my PC, but when I open my phone there I only get a DCIM folder with the photos on the phone. The ringtone does not show up.

I have also tried "Transfer purchases from iPhone" and it still does not show up. I have tried backing up my iTunes library and I still can't find the audio on my computer.

I have spent about 3 hours trying to figure this out and am appalled by the terse instructions left by commentators. "Sync the iphone 4 to itunes, then convert the file to an M4R, then upload the ringtone to your iphone 5".....Do you think if I knew how to do this I wouldn't be on here asking for instructions on how to do this? Please, give detailed steps and not summaries. I am computer literate, but these terse instructions are just ******* me off, because I spend more time googling how to do those and then I find out they don't even work.

Why can't I just drag the file from itunes to my desktop and have it copied that way? Or why isn't there a "save as" option to save it to the desktop?

Any detailed instructions about how I can save this ringtone to my Mac or PC would be much appreciated.