If you get to the point when the COBie Toolkit 1.4 dialog opens, use the upper Import button to read the IFC file that you wish to convert.
Then use Export/Report to convert it. You have to select the file type on the Save dialog.
COBie SpreadsheetXML (2003) is the most common format.
It is worth to mention the Options button of the Toolkit. By default certain IFC entities (for example the walls) are not converted to the Spreadsheet. You can set this ignored entities template under Options/Object IDM (Ignored Entities). Please note that you have to do this setting prior to importing the IFC file.
Hope I could help, let me know if you have further questions.