A true, true friend would definitely share their music resources with you—and FimFan14 has done just that. He worked up a whole bunch of resources for A True, True Friend, and they're sure to be useful.
You can listen to FimFan14's piano rendition in the video. Then there's sheet music so you can play it yourself. There's also a midi version. And there are two mp3 files: one with vocals and one without vocals.
Thanks a bunch, FimFan14!