Remove 
Use the Remove option to select and then remove underlays from the screen.
Underlays may be:
- Layers that are loaded as an underlay (through the File > Underlays > Load Layer option).
- Mapfiles that are loaded as an underlay (through the File > Underlays > Map File option).
- Grid mesh models.
- Triangulation models (images that are draped over a triangulation are also removed as they share the same graphics segment).
- Contours that have not been put into a design layer.
- Slices, blocks and boundaries of block models.
Instructions
On the Design menu, point to Map Control Points, and then click Remove.
If there is only one underlay loaded, then you will be asked to confirm the removal. If there is more than one underlay loaded, then you will be asked to select the underlay to remove.
