Your objective in order to get this achievement is to provide a homeless man with several items. He can be found in one of two Subway entrances on Laymond Avenue.
The first item is a candy bar. In order to obtain it, you must use money on a vending machine that will either be on Campbell St. or in the alley before it.
The second item is a coat that can be found in a department store on the street behind the movie theater.
The third and final item is found in the dock area off of Rice Street. The location changes a little depending on which difficulty you're playing on, but it's always around the same area.
On Easy difficulty, it can be seen leaning against the dock just as you enter. On Normal, the rod is across the street from the docks entrance, down a ladder in a fenced in area, and on the right side by some barrels before entering the sewers. On Hard difficulty, enter the docks and on the right side, between two trees is a hole in a fence. Go through this hole onto a wooden walkway, and the fishing rod will be seen in the back of this area.
Return to the homeless man to unlock this achievement and gain access to the entire subway system.
Taken from:
https://ca.ign.com/wikis/silent-hill-downpour/Will_Work_For_...