The downloads from Sonar are in csv format and use a ";" as delimiter between columns. If you open it in Excel it should look correct right away. If not you can try it this way:
Option 1: Drag & Drop
Open a new sheet in Excel
Locate your downloaded Sonar .CSV file
Drag the .CSV file with the mouse to your new sheet in Excel and drop it.
If this option does not work for you, you can open the .CSV file in the following way:
Option 2 : Using Excel Text Conversion Wizard
Open a new sheet in Excel
Go to the "Data" tab
In the Get External Data group, select “From text”
Navigate to the location of the Sonar .CSV file (i.e. in the download folder) and
open the fileClick "Next" in the Text Conversion Wizard in step 1
In step 2, choose the semicolon as delimiter, click "finish" and then "OK"
Sonar Tutorial with Export Explanation (starting at 3m30)