how do I make a tile altering event?

[Disrok]

title says it all but specifically I want to know how to make a event which will change the none active volcano into the active volcano without changing maps
(you can find the tile im talking about in TileB)

[semic]

make it into an event, and have a self-switching event on it. So either when player touches it, it switches or time-based it switches itself.