Here's how Princess Celestia, Luna, Cadance, Sharon, and King Solar Flare restore peace to Quahog in The Day the Griffin's Came Part 2.
[the sun then rises and we see the corpse of Smaug still in the Everfree]
[It fades to Quahog]
Princess Celestia: This is it.
Princess Luna: Let us begin.
[Princess Celestia, Luna, Cadance, Sharon, and King Solar Flare light up their horns and then there eyes glow as Quahog is returning to it's glory as "Crack of Doom" plays and the clouds clear revealing the sun they are brought back down as everyone cheers for their long-time town reborn]
Brian: Thank you. After all these years, Quahog is back!
[Everyone cheers louder then they all started saying "All hail, King Brian Griffin"]
Brian: My friends, I thank you for being by my side for all these years and Now we can return to our home! And I am no longer Brian Griffin, I am "King Brian Griffin"! And we shall stay here for peace with the dragons!
[everyone cheers as the episode ends]