Remove tiles from the tilemap with the Eraser tool
Use the Eraser tool to remove tiles from the tilemap by selecting the tiles in the Scene view with this tool.
Select the Eraser tool from the toolbar, or press its shortcut key D. You can automatically switch to the Eraser tool when using the Paint tool by holding Ctrl while using the Paint tool.
Erase tiles on the tilemap in the Scene view by selecting them with the Eraser tool.
To adjust the size of the Eraser tool, click and drag the tool over the cells in the Tile Palette window until you achieve the desired size (tiles in the Tile Palette window aren’t erased).