how to replace office 365

I have just installed libreoffice. How do I start using it instead of Office 365, which is running out of its subscription today?

Thank you for the answer. I have hundreds of text, pdf and Excel files, do I have to go through each one separately opening and re-saving? Once Microsoft Office expires later today, will I lose access to my old files if I haven’t already opened and resaved in odt format?

You start LibreOffice and open the files (MS) you have. You can edit and save it again, preferably (in Writer) in * .odt format. You can find the documentation for LibreOffice here.

Thank you for the answer. I have hundreds of text, pdf and Excel files, do I have to go through each one separately opening and re-saving? Once Microsoft Office expires later today, will I lose access to my old files if I haven’t already opened and resaved in odt format?

No, you should only open and save the files that you need at the moment. odt and the other file formats of LibreOffice are called OpenDocumentFormats. It is, so to speak, the house format of Libreoffice. If you later change back to MS, these formats can also be read and saved there. There can be small differences in formatting each time, so it makes sense to save the format offered by the particular program you are working with. Both formats, ODF and MS can be understood by both programs.

Thanks very much for your advice and re-assurance.