You need to get a Quicken installed on your computer and then use it to open a QDF file. Once you have a QDF file opened, export data as a QIF file and use the ProperConvert app to export your data to CSV or Excel/XLS/XLSX format.
Search for "Quicken download" and find the latest Quicken installer to access a QDF file. If you know for which Quicken version your QDF file is, download that Quicken installer or next year Quicken installer to access the file (in case your QDF file version is slightly higher then downloaded Quicken verson).