In the carnival level, you will find a strongman bell minigame. It is right before the bumper cars, so if you go past those you have gone too far. You have to hit the red pad w/ any melee weapon, but there is a catch, you must have adrenaline active to make the bell ring. If no one in your party has a shot, then simply travel through the level until you find one and make your way back.
Edit: It has been proven you can use ANY melee weapon. This includes the katana that you frequently find in the picnic tent near the minigame. As long as you have adrenaline, you are good to go.