Prepare for this mission before going since there are lots of enemies here. Make sure to bring firearms, snack, meds, and explosives. If you still need more items, you can try the supply locker in the survivors' building. Talk to Becca to initiate the mission.
Your goal is to defend the survivors while they are doing some construction. All of the zombies during the mission are easy to dispose however your main concern will be the Juggernaut that will eventually attack your company. Mainly use explosives especially firebombs like Flame Fougasse to damage it quickly, shoot it in the head as long as you have ammo, and run it over using a vehicle as well. Just make sure to hit it while reverse driving to prolong the durability of the car.