Keyflower - how do you upgrade a tile?

[robotco]

how do i upgrade a tile in Keyflower?

[DragonNinja]

You make use of the transport tiles, either yours (in which case you'll get the worker back in the next season) or your opponent's. The tile lets you move resources a total of a set distance after which you get to upgrade a tile (or 2 for some upgraded tiles.) assuming the resources needed are on the tile you want to upgrade or you have the tool needed for the upgrade. The game will prompt you to select a tile to upgrade assuming you have tiles available for upgrade.

[robotco]

thanks