1. Click Grids | Edit | Convert.
2. In the Open Grid dialog, select the grid file and click Open.
3. In the Save Grid As dialog, choose to save the grid as a Surfer 6 Text Grid and click Save.
4. Click OK in the Export Options dialog.
5. Open the text grid in a text editor, like Notepad.
6. Switch the third and fourth rows.
   1. Select the fourth row and click Edit | Cut.
   2. Insert a new row after row 2.
   3. Click Edit | Paste and paste the information as a new third row.
   4. Delete the blank row
   5. Click File | Save and save the changes. Close the file.
7. In Surfer, click Grids | Calculate | Transform.
8. In the Grid Transform dialog, click Browse in the Input Grid field.
9. Select the newly saved text grid and click Open.
10. In the Grid Transform dialog, choose Operation = Rotate and Angle = 90 (to rotate 90° counterclockwise) or 270 (to rotate 90° clockwise) and click OK.

Updated October 16, 2018