Instructions
Press "Circle" to change character classes. Select the class with the regular hat (the worker class).
Gather the required wood and metal necessary to upgrade the building. Press "L1" plus "Square" over the wood and metal to gather.
Locate the green arrow above an upgradable building or location. Hold "L1" to turn the arrow from green to red. When the arrow turns red, press "Square" to start upgrading the building or location.