Well... you won briefly... but here I am yet again taking the trophy.
Honestly... not hard at all. The LH has a lot of repetitive patterns, and it's just the Right hand that has a lot of frills.
I used to do things like this, but I got in a little bit of trouble charging people to transcribe other peoples (copyrighted technically) material.
I transcribed a piece for Ted a couple of years back and all I had was an MP3 of inferior quality to that, and I did a pretty good job.