Well ya just do what I did in the movie.
Anyway I found out by super jumping the chandeliers you can get to the top of the Snowpeak Ruins foyer where you're not supposed to go yet.

There are 2 doors up there. It requires some clever boomerang tricks, I think people call it a sequence break.
I wanna post a movie but I think I said in my YouTube description I would let other people find stuff with this one instead of hogging it all to myself, lol, so it would look a little silly if I did.