"Claptrap has informed you of the nearby zombie infestation. The town is normally kept safe by three defensive turrets, but they don't yet recognize zombies as a threat. Your only hope to restore any semblance of security to the area is to recalibrate the town's defensive batteries."
Recalibrate the defense turrets
Turret 1 calibrated
Turret 2 calibrated
Turret 3 calibrated
1. Head into town killing zombies. Hug the right wall as you go down.
2. As you enter the town you should see your 1st turret on a platform to your left. Jump to the platform and recalibrate the turret. Once the first turret is recalibrated things get easier as it starts firing upon the zombies in the area.
3. From here you can easily spot the other 2 turrets. One is to your front left and the other is to your front right.
4. Activate the remaining 2 turrets and the zone is now safe.