If I will to change a chapter in the book, I will change the event when Troy let the offered horse statue brought inside their wall. If only they have burn it instead on bringing it inside, troy wasn't burned. If they have burned it, they could have won the war.
If that could have happen, the story will be like this:
Sparta made a giant horse and inside of it was the soldiers of Sparta. They made this so that they can sneak inside the walls of Troy. When King Priam and his soldiers saw this, others said that this was an offering for Poseidon so Spartans would have a safe trip but King Priam didn't accept the fact that it was an offering, so he demanded that it should be burned. When they have burned it,some good soldiers died and other Spartans that was hiding attacked the Trojans. Sparta, having few strong soldiers, fight the Trojans. But Trojans have many soldiers than the Spartans and Trojans have the skillful archers in the world that time so the Trojans won the war.