I already posted long ago what I would do to change the fate of Lucas North.
I feel a bit more reluctant to change the fate of another character near and dear to my heart, Thorin Oakenshield.
But yes, with apologies to Tolkien, I would change Thorin's fate.
(What about Fili and Kili? I'm really emotionally torn here. I would save all of them, but I'm just going to dry my tears and talk about their uncle)
So here is my wish.
Let's think back on the final battle with Azog. Remember when Thorin throws that ball-and-chain thing, what is that called, to Azog and he goes underwater. I would have Azog drown and die, and the battle end there.
But we need a sad scene with Bilbo. So right before Azog goes under the water, I would have Thorin momentarily lose Orcrist, and he is badly wounded by Azog. When Bilbo finds him, just as we see in the film, Thorin thinks this is the end. He says his famous "last words" to Bilbo.
But Surprise! The eagles have heard Bilbo's plea, and they bring Oin to Thorin, and he saves the day.
Thorin, who is now King Under The Mountain, recovers after a long convalescence.
The long recovery time gives Thorin time to think. His heirs, Fili and Kili, are gone. Thorin needs an heir. He consults with Dain, Balin, Dwalin, and Bilbo about what he should do to find a future bride. Dwarf princesses are a rarity and a treasure.
A call goes out to the Seven Dwarf Kingdoms for a suitable bride for King Thorin. To Thorin's surprise, every single eligible dwarf maiden in the world of dwarves want to be his bride.
Even eligible ladies from the world of Men and Elves apply.
Thorin feels he will never find the same true love he lost that fateful day Smaug came to Erebor long ago. But he must choose.
What would you advise King Thorin to do?