First, to access these upgrades, you must be at least level 16 and have at least 550 people already living in your town. From there, you'll see the familiar blue and green upgrade arrow sitting on your Ranger Station, after you've collected its profits (where applicable). This brings up the Upgrade Menu, which allows you to begin the process of collecting the five bulk ingredients needed to actually upgrade. You'll need:
- 4 Caterpillars
- 4 Frogs
- 4 Water Canteens
- 4 Compasses
- 4 Smores
After this has been done, your Ranger Station will receive a slight visual upgrade (the watchtower looks to grow a bit taller and the roof changes colors), it will grow to support 480 citizens instead of 330, and you'll also trigger the second set of upgrades. It should be noted that this set doesn't have any population requirement to unlock, so you can jump straight from one upgrade into the next. The process here is the same, except you'll need to collect seven each of the above ingredients, rather than four.
For finishing this second set of upgrades, your Ranger Station will change again, getting a new forest-green roof and an even more advanced watch-tower. You'll also then be able to support 840 citizens with the building, which is actually a fairly hefty boost. Just keep in mind that these upgrades aren't permanent if you sell your Ranger Station(s); upon rebuilding them, you'll have to upgrade all over again, so do so at your own risk!
Do you have a Ranger Station in CityVille, or was it one item you chose to skip? Will you build one now just to upgrade it? What do you think of these upgrade requirements? Sound off in the comments.