Travel to New York to meet up with your father in the markets. Follow him through New York to the warehouse by the docks. Walk out of the alleyway that you are in and head for the red marker on your map. Cross the street and head for the road just to the right of the large wall. Follow this to the end and then turn right again. You'll see your target in the distance beyond a cart filled with hay. DO NOT enter the hay stack because if you kill him and drag him into the hay, you'll fail because you can't get his uniform from here.
Go past him and around the corner. From there, use the corner for cover. Wait for the Red Coat patrol to start walking away from him, whistle over to him and then kill him when he comes close. Loot his body. You'll meet back up with Haytham and follow him into the building to end the memory.
