If you're after completing this achievement ASAP, open the spoiler. If you are after enjoying the story without spoiler, just continue playing as you would and this will eventually unlock.
Things might be a little different for you as choices affect how the story goes.
*** Spoiler - click to reveal ***
You'll encounter the Admin. Move forward and then to the left when prompted. Afterwards move further to the left to not get seen. Xara will then try to attack Romeo but fail. Take Oliva and Axel with you and head off the street.
Once you gain control over Jesse, walk to the far right and pull the lever to reveal Elytra wings. Afterwards move forward to see Nurm has been freed by Ivor. Tell Jack to play it cool. A plan comes together on how to enter the tower, involving fireworks and a bucket of water.