To get this trophy you must complete the quest "Alduin's Wall" which is a part of the main story and cannot be missed.
*** Spoiler - click to reveal *** You will begin this quest after completing the quest "A Cornered Rat and speaking with Esbern in the Ratway. Your first task is to escort Esbern to Riverwood. Go back the way you came towards the exit of the Ratway. You will have to fight some Thalmor Soldiers on your way out.
Once you are outside of the Ratway you can fast travel to Riverwood. Head to The Sleeping Giant Inn and speak to Delphine. After learning about Alduin's Wall, you will be tasked with going to Sky Haven Temple which is next to a base called Karthspire. It is near Markarth so you can fast travel there or take the carriage for 20 gold if you have not discovered it yet.
Once you reach Karthspire you will have to fight a wave of Foresworn enemies as well as a blood dragon. Once the enemies are defeated, head inside the cave where you find another batch of forsworn. Once they are defeated, move ahead until you reach a set of three pillars with symbols on them. Esbern will tell you that the symbol of the Dragonborn has a downward pointing arrow on it. Rotate all the pillars until they show that symbol and a bridge should come down allowing you to proceed.
Shortly after you will arrive at an area with pressure plates on the floor with symbols on them. You need to follow the path with the same Dragonborn pattern to the other end of the room and deactivate the trap. Once that is done you can proceed.
You should now arrive at the entrance to Sky Haven Temple. Move to the center of the room where your quest marker is pointing you to and activate the blood seal, granting you access to the temple. Once inside, wait for Esbern to reach the wall and speak with him. He will tell you about a shout that can knock a dragon out of the sky. At this point Delphine will talk to you and direct you towards learning about the shout from the Graybeards. After this dialog, the quest will finish and the trophy will pop.
*Cross-posted from Skyrim (PS3) trophy guide