You can import a DXF, SHP, or other vector file into Surfer as a 2D base map, or you can create a grid from it to display as a contour map. 

To load it as a 2D base map, click Home | New Map | Base | Base, select the file, and click Open.

To recreate the contours as a customizable contour map, the vector file needs to contain Z value information. 

1. Click Grids | New Grid | Grid from Contours.
2. In the Grid Contours dialog,
   1. If you created a base map from your vector layer, select that layer from the Contour Source list. Otherwise, click Browse, select the file, and click Open.
   2. In the Select Field dialog, select the attribute field containing your Z values from the list, and click OK.
   3. In the Options section, check the box next to Partial contour cleanup.
   4. At the bottom of the dialog, choose Contours from the New layer type list.
   5. Click OK.  
   6. The grid and map are created. You can now select the Contours layer in the Contents window and edit the contour level properties on the Levels page in the Properties window.

Updated November 1, 2021