Right now there are only the following 7 languages (ru, de, es, fr, it, pl, ja). i.e.:
Feel free to ask for more languages here.
Installing is as simple as running:
pkgman install libreoffice_de. Naturally, you can use HaikuDepot too.
Note, that right now LibreOffice doesn’t read Locale settings for some reason, so you will need to set your language manually in Tools -> Options -> Language Settings