Below the product listing, you will find a box listing all available fields for products. On the left hand side of each field, there is a checkbox to select the field. Check the boxes for the fields you wish to include in the export and then click 'Set fields' (1) below the box.
The file created is of the file format CSV. This file can be opened in any spreadsheet sofware. Listed below are som links with instructions on how to open a CSV file in the most common softwares.