I'm not sure if MS isn't still sabotaging support, but Europe did force them to implement exporting to the open document formats. You should be able to convert

I'm not sure if MS isn't still sabotaging support, but Europe did force them to implement exporting to the open document formats. You should be able to convert all your docx / pptx / xlsx files to odt / ods / odp before switching, or just using Wine as a conversion tool.