I have LinuxMint 8.2 and it is in Swedish. I would like to have automatic update of LibreOffice but can not find it, though it's in my help how to get started

As I say in the title, in my Swedish LibreOffice there is no page called something like Automatic Update.

LinuxMint 8.2

Really? Current version is 18.2

automatic update

If your LibreOffice is regularly installed, so in each complete update (mintupdate) it is regarded, if the repositories have changed.

You also can try sudo apt-get update && sudo apt-get upgrade -y or sudo apt-get update && sudo apt-get dist-upgrade -yto update the terminal way. Be aware that automatic updates in Linux often are later than updates from the LibreOffice website or the PPAs. Sometimes the Linux updates are finished before last edition…

Regarding the “page” in your LibreOffice: There is no way, even not in Windows, AFAIK ;-).

If you want an upgrade on LibreOffice 5.2.x; 5.3.x; 5.4.x so be informed that this only can be done via PPA or downloading from LibreOffice website. If you install the regular way (i.e. not in parallel), you should de-install the previous version before.