Climb the ladder that's near you.
Shimmy along the little wooden board.
Then once you've past the crate that's blocking the walkway, get up to walk in the wooden board.
Now, head straight and use the zipline.
When you land, you might catch on fire. Jump up to the hole on the pipe.
Proceed to head in.
Crawl through the pip until you get to the ladder. Climb it.
A technician will be on his way somewhere. You'll have to follow him.
Climb this ladder to get up so they can't see you.
Then, walk around the walkway and jump on this blac box thing.
Jump up to get on the pip and shimmy to where the briefcase is.
Then wait for an enemy to come and take him out.
Walk up the stairs that's on the right.
You'll find a little crevice here. Enter it to sneak up on a guard.
Take him out.
Go through the walkway that should be behind you.
Make sure you go right.
Then turn left where a guard should be.
Take him out when you get the chance.
Then go through here instead of the walkway inside the building.
Climp on top of this thing to your right.
Shoot the windows to help it break.
Then, wait here for the explosion to come and the window breaks.
After the window breaks, shimmy to the next room.
When you get down to the ground, go to your right where a walkway will be and go up the stairs.
Go through that alley that's ahead of you.
Go down the stairs that should be ahead of you.
Head in the doorway.
Turn right and enter the door.
Go through this doorway next.
The guy with the briefcase should be right there or getting there.
Then, grab the briefcase.
And thats it!