I use open office - how do I update

There may be an "Update" option on one of the menus, perhaps the "Help" menu.

FYI, you may want to consider using LibreOffice as it was forked from Open Office years ago and has a lot more developer activity with many updates & improvements since it was forked. Plus LibreOffice has migrated away from most of the Java code.

https://www.libreoffice.org/

Go to the same website you acquired it from (unless that was not the Open Office developer's website).