1. Download APK first, then copy to your Android device's SD card

2. Install APK, DO NOT open app

3. Download obb files, then rename to 'main.102281050.zombie.survival.last.city.shelter.obb'

4. Copy obb file to /SDCARD/Android/obb/zombie.survival.last.city.shelter/main.102281050.zombie.survival.last.city.shelter.obb