I have found the easiest method for Dying Lights super annoying challenge 'Dying Lunch' which is to get 30 headshots within a set time limit. Aiming down the sights and picking off the zombies around the spawn area ( near the bus) first and then using a Stasis Field Projector grenade on the Big goons to freeze them. Freezing the Two Goons at the spawn gives you an easy and fast 10 headshots, as you can rack up 5 each from these. Now move up to the highway to pick off the reset of the zombies by aiming high and spamming rifle shots into the crowd.
