Here's a video guide for this achievement.
Before starting, you will need pretty much the entire map opened, power turned on (get zombie hand from the beach and place it near the electricity grid) Each trap costs 750 points so you will need
3750 points as well.
There are 5 traps to restore, this is how you restore them:
In the building where you find Elvira and where you can change the color of the outlay of the map, there is a trap which can always be turned on.
Power Trap: Where you turned on power, turn 180 degrees and you will see a box on the fence. Walk straight ahead and you can retrieve something from the trash can in front of the yellow building. Place that in the box mentioned earlier and this trap is restored.
Freezer Trap: Retrieve a piece from the gas station. When facing the large red doors which are opened for the easter egg, face left and go around the corner. In a trash can against the wall you can retrieve a piece. Place that piece inside the freezer cell in the supermarket, and this trap is good to go.
Pool Trap: You can find this near the pool, on the other side of the bridge near the motel. Walk in the direction of Elvira, then turn left and from the truck you will see now, retrieve a Jerrycan of gas. Use this to restore the pool trap.
Fire trap: You will find the trap on the side of the beach. It is a large storage tank for fuel. Retrieve the a piece from one of the picknick tables in between the building in this area and the pool area. Use that piece to restore the trap.
Keep in mind all of this has to be done in ONE game. If playing in coop anyone can restore the traps but you need to activate them.