You can only open or export the form to Excel or as a PDF file. Neither of the two options you choose, you'll need to manually convert them to Open Office.
Here are the steps:
Open a file in Acrobat.
Click on the Export PDF tool in the right pane.
Choose spreadsheet as your export format, and then select Microsoft Excel Workbook.
Click Export. If your PDF contains scanned text, Acrobat will run text recognition automatically.
Name the Excel file and save it in the desired location.
For more information on downloading W-2s, click here.
Here's an article for the list of payroll reports that can be exported to Excel in QBDT: Excel-based payroll reports. It also provides a step-by-step guide on how to generate them in the system.