changeTile(change, changeX, changeY, stackBypass);
change: tile’s name, example “dirt”.
changeX: tile’s x value, example 244.
changeY: tile’s y value, example 244.
stackBypass: either true or false (or nothing), if true, it will place the tile on top of the stack of tiles at that x/y.
You may also want to call
game.updateTiles = true; so the change is shown immediately.