There is little chance to bring over all metadata.
However, you could transfer over your ‘played’ statistics.
- shut down Plex server on the mac
- copy the main Plex database file to a safe location https://support.plex.tv/articles/202485658-restore-a-database-backed-up-via-scheduled-tasks/
- set up Plex server on the windows box. Use the same Plex credentials you are using now on the Mac. Create a small test library to test principal functionality.
- disable automatic and periodic library updates on Windows https://support.plex.tv/articles/200289526-library/
- Shut down Plex server on Windows
- copy the database file you saved earlier over to the Windows box, replacing the one that is already existing there.
- Start Plex server on the Windows box.
- Edit your library(s) to include the new paths to your media files. Windows and Mac have different approaches to describing the location of files, so this has to be changed.
- Scan Library FIles for each library (this may take a long time)
If you have experience with both Mac and Windows and are not shy of the command line interface, you could edit your database file directly, to change all Mac-style file paths to Windows-style file paths.
This will be of benefit particularly to media, which are not matched or which had manual edits to their metadata.
see [HowTo] Plex database modification - Moving media the right/wrong way
