Leave the apartment after the cutscene. You'll hear a little girl crying, enter the playground right in front of your apartment and approach her.
Follow her to the side of the playground and she'll go through the hole. Since you can't use that hole in the mesh, climb up the boxes and jump over the fence.
Run out of the alley and turn right. Use the light post to cross towards the other side of the street and once again follow the kid.
She'll enter into another hole, turn left when she does and you'll find some platforms that you can use to get to the other side.
Turn right once you get to the other side and follow the alley down to the mesh closing of the playground. Hop the fence and prepare to get harassed.
Don't move and don't pull out your gun. Wait for one of them to approach you and surprise kill him. Now quickly point and shoot your gun towards the guy on the left. You'll pick up a bullet as soon as you kill the first guy so you'll definitely have enough to kill 1 guy.
Then point your empty gun at the last of the thugs. Approach him while he's still scared of you and perform a struggle kill.