Use the metro to head to the area with the club in it. It will be highlighted on the Metro Map. Follow the waypoints until you find the manhole cover. Head down the ladder to the front door of the illegal gambling club. This will trigger a cutscene. Speak to the boss. It won't go well and you'll be asked to leave. Leave the club and follow the tunnels until you find a gate that can be hacked. It's to the right of the club entrance. Hack it and head back into the restricted zone. Get ready to steal some goods from some criminals.

You'll run into a camera on the other side of the gate. Just stay out of its vision cone when you pass it. Head under the floorboards, which will take you to the other side of the room and to a locked door. Hack the door and get inside. Be sure to abort the hacking process if you're on the verge of being caught, as it will trigger alarms. There's a vent inside the room that will take you directly to the room you're looking for. The far side of the room has a locked safe that has the augs you're looking for. The hack is simple enough, or you can use the code 6446. Exit the compound the exact same way you came in. Your friend will tell you he's not ready to see you yet, and he'll contact you when he is.