Ok Phillip, I'll try.
We want as much as possible of the Ainulindalë in visual form, right? But the Ainur don't have sight until Eru makes the Music into a vision. And we don't want VoiceOver.
So, first we have the frame narrative. In the frame, we see Elrond begin educating Estel. This begins with some lesson about Eru and the Music, which of course intrigues us (and Estel) but feels a bit abstract. "Was their Music like this music?" - but Elrond says, "not quite". He perhaps says it can be felt in a waterfall, seen in the clouds, and so on.
From this it gets tricky. We want to leave the frame and leave this situation where one person is telling another person stuff. We need to get to the beginning. The problem is, the beginning is in three parts. First, the Music. Then the Vision. Finally, Eä. Maybe it's braver to just do it all in one long go, but I feel the Ainulindalë has something to gain by being told in flashbacks, and the first part is still sound only, so my suggestion is that Elrond describes the vision briefly and then goes to the Eä moment. We're then directly thrown into the birth of the world, and then we see the Ainur enter and take their forms (which resemble their memories of the Children of Ilúvatar from the vision), and find the things that seem to be things they themselves devised in the Music, as Eru said. They get to shaping Arda, which at first I picture as a bit chaotic; Ulmo revels in rain and wave making, Manwë is flying high in the sky, and Aulë and his followers pull and push heavy matter into land, into islands, into mountains. And as they get into their love for the elements, their physical form is affected by those elements, so that Ulmo gets more and more "oceany" and so on. After a while the first (sub)creative rush subsides and there must come a need for reflection, a time for the Ainur to communicate and maybe do some planning, and so, while they continue their playful work, they might show each other different ideas and cooperate, like Manwë perhaps sweeps down, joining Ulmo in creating waves, or Aulë could help making fjords; and they might say to each other, "it's like the Music, remember?" or "the Vision is made real!" And we get a flashback from Ainulindalë. Or they could reflect and say something like "This is Eru's work, his creation, but just like in the Music, we can adorn it after our own heart". Now the flashback can be pretty extensive here, I think. The difference, compared to beginning with the Ainulindalë, is that in this way, we begin when the Ainur is visible. They have bodies. And we can use this as a pretext to sneak in some visual effects into the parts of Ainulindalë which otherwise are just sound. (And in the Vision I believe only the Vision, not the Ainur, are visible?)
One logical ending fpr the episode would be the Vision. In it we see what the Ainur are longing for and anticipating through the season - the coming of the Children of Ilúvatar; it's the theme of the season.
Now I hope I've been at least slightly clearer. I'm happy to elaborate if necessary.