How can I convert Word document to Libre Office Writer?

I have a Word 2007 document on my saved on my computer that I cannot add or change anymore since I don’t have a MS-Word program anymore.
How Can I change that document to Libre Office now?

Thanks

Just open it in LO Writer. After that you can save it as ODT.

Adding to this simle answer: You can also batch-convert all your MS-Office files in one go from the File-menu → Wizards → Document Converter…

When in your file manager/browser, right click on the Word document, mouse over Open With, and select LibreOffice in the list. If it is not in the list, click on Other or Choose Program and navigate to LibreOffice.

Once the file has been opened in LibreOffice, click File > Save As…

Choose where to save the file, and then click on the box next to File type:

Select the (probably first) format in the list: ODF Text Document (.odt) and click Save.

The document is saved in ODF text, which is the default formant of LibreOffice Writer.

If you are using the portable version of LibreOffice (from portableapps.com), you may not be able to follow Brian_I’s exact method because you may not see LibreOffice in the offered list of programs. In that case, start LO, select Open File, navigate to the file, and open it. The proceed as per Brian’s instructions. You could also leave it as a .doc or .docx file and just continue to use LO to open it. That makes it more exchangeable with others who may be using Word, but may lose some formatting and may create a larger file.