Go to multiplayer, private match, choose the Hotel Elysium map and start the match. You'll spot the hot dog cart pretty easily keep an eye on it and don't let it blow up. It needs to survive to wave 5. Once the boss spawns (the big guy with the gatling gun) shoot em until he goes to his knees, and leash or kick his helmet off. Let him get up, lure him somewhere near the hot dog cart, and shoot em till he drops to his knees again. Kick or leash cart in to the boss for the kill. and boom goes the dynamite. See video if needed, good strategy to stay alive until the boss comes is go to the bar. kill kill kill duck if needed, leash and kick in to sparking wall, upgrade health and defense if necessary.