How did the greeks finally get into troy?

Answer 1

The main fact was that Troy, was invaded by a Trojan Horse, a big giant wooden horse that held the Myrmidin and Achilles, thus letting in the Greeks who slaughtered the Trokans in open-combat.

Another theory is that Troy had an earthquake, causing the walls to collapse which let in thousands of Greeks, and Troy's destruction.

I hope this answers better than:

"with th Trojan horse" the fool who wrote that.
According to legend, a group got in in the belly of a giant wooden horse, and then opened the gates to those waiting outside.

Answer 2

After multiple failed attempts at storming the gates, Odysseus came up with the idea of building a giant horse that would hold a handful of hidden troops. Since there were fewer soldiers, they could use wood from ships they no longer needed. The idea was that the Trojans would take the horse as a trophy since the Greeks would be seen sailing away.

The truth was that the bulk of the Greek army sailed and hid behind a nearby island, leaving a soldier named Sinon behind to explain the horse. He told the Trojans that the Greeks had fled and that the horse was an offering to Athena, to repent for the sacking of one of her temples. It was so large, he further explained, so that the Trojans couldn't move it into the city and take that favor for themselves.

Of course the Trojans DID move it into the city, against the warnings of the prophet Laocoon, who famously exclaimed "Timeo Danaos et dona ferentes" or "I fear the Danaans (Greeks), even bearing gifts...". For his trouble, Poseidon sent a great serpent to strangle Laocoon and his sons, to prevent his message from sinking in. When the people of Troy went to bed, the Greeks exited the horse, and took over the city in the cover of night.