Note: Before you can accept this mission you must unlock the Brandon Docks ctOS Center. This can be done earlier in the game or undertaken directly before.
You need to infiltrate the Racine Boat Restoration yard in Brandon Docks to find the man working for Damien. There are multiple ways to enter the building, each with advantages and disadvantages.
With lots of cover opportunities and very few guards in the vicinity this is a good entrance to begin a stealth route. From the entrance you can take care of most of the outside threats without entering the Warehouse, which is heavily guarded. Close the door to the Warehouse to keep the guards inside from seeing you violence outside.
Entering though the door, rather than the main gate, the area has less cover but still serves as a good entrance to take out the exterior enemies. Watch out for the guard by the southern Warehouse ramp that can spot you when you take out the first guard. Close the door to the Warehouse to keep the guards inside from seeing you violence outside.
This access point will have you take on the enemies in the Warehouse first, rather than last. It is a great spot to begin an aggressive route, letting you take them out without being pinned down in the open.
Once the guards outside are taken care of you will need to deal with the final four guards in the Warehouse, one of which is an Enforcer. Open the door, if you closed it during you rampage outside, and then hack the camera by the door. You can now choose to hack the cameras to find the Head Office access code or kill the guards inside.
I find it easier to simply take out the guards so that the rest of the mission is easier. The Enforcer should be your main target, since any actions against the guard will cause them to become aggressive and dealing with him first will make the rest of the guards easier handle. From the camera in the Warehouse you should spot an explosive panel on the floor that the Enforcer will walk directly by. Hacking the panel will cause a chain reaction to kill both guards in the area and you can deal with the final two guards, who have no idea where you are.
After clearing the area, search for crafting items and grab the Audio File: Damien Brenks 03 from the Warehouse. Make sure to hack the access code from the downed guard and head upstairs to the Main Office and hack the computer for a scene.
Racine is on the run and we need to catch him before he gets away. As you leave the office an Enforcer will be waiting to attack, but he has been stupid enough to stand right next to a junction box. You now need to head after Racine, but rather than heading south toward him you should head north for a car. Grab a durable vehicle, or truck, and then drive directly west. Racine will drive west and then turn north at the second intersection, where you can wait to hack the light to slow him down and slam into him to stop his progress.
Racine will hop out of his car and head off in search of another one when his car becomes inoperable. Make sure to ignore his reinforcements and run him down to complete the objective and then escape.