Click "Customize-Tile Flooring" and select the wall or floor to enter the tile flooring interface. Select the surface and you can replace the material by clicking on the material thumbnail in the "Edit" section on the right property panel. Click "Finish and Back" to exit the tile customization interface.
In the general design interface, you can also select the floor in 3D view, and replace materials by clicking on the material thumbnails in the "Edit" on the right property panel.
