Confront Johnny “Two-Dicks” Peralta

Head to the Wilcock’s Sports Bar. The best way to approach this location is from the back door in the alley west of the building. This will take you directly to stairs where you can easily reach the boss and the pile of money along the way.

If you want to get rid of all the enemies, use your intel view to know the sniper nest on the rooftop and take out the sniper there. There's also a Tac-Vest on the floor beside the sniper. You can then proceed sniping the enemies below then ambush them from the stairwell. They’ll be stupid enough to keep coming up the stairwell in an attempt to reach you.

When the enemy population has declined, go downstairs and make your way towards the boss. He has two other bodyguards with him. You can lob a grenade inside to take the bodyguards out and disable the racket boss. In the same office, there's a Vargas painting and a pile of cash for the taking.