Kill the living garbage so that James Filth can get back to work.
When you return to Hobo Alley after finding the Steaming Bolt in Case 2: The Game Is Afoot, speak to James Filth on the corner of the intersection of Cheswick & Grove to open this case.
After James tells you of his plight, destroy all 10 pieces of animated trash around Hobo Alley. The number of garbage cans in each battle will vary, and they'll occasionally fight alongside hobos and Fruit Fuckers.
Once all the garbage has been taken out, go back and talk to James. He'll reward you with a red token for the Pelican Bay boardwalk souvenir stand, closing this case.