In most cases, you shouldn't need to change the primary field in your table. However, if you need to do so, such as after importing a CSV, we recommend that you first create a new, empty column. Then, click the primary field header cell to select all cells in the column, then use Ctrl+X (Cmd+X on Mac) to cut those cell values. Next, you'll paste those values (Ctrl+V/Cmd+V) into the empty column. Finally, you can copy and paste cell values from another field into the primary field.