How to change language quick

[AyVi]

Is it possible to change language of the user platform? everytime I got to options > language > brugerflade/user platform there's no other opportunity than my language

Do I have to uninstall and redownload open office to change language of the board (check picture)

Or can I change language another way (sprog = language)?

[keme]

You need to download and install a language pack.

With that in place, go to OpenOffice.org - Preferences (perhaps "Brugervalg" or "Indstillinger" in Danish, keyboard shortcut Cmd+semicolon).
Alter setting in Languages - Language - User interface ("Sprogindstillinger - Sprog - Brugerflade"?), then restart the OpenOffice suite to make the change effective (you have to quit the application, Cmd+Q ; closing all windows is not enough).

Also, it may be of interest to you that there is a fairly active Danish user forum.
(The Norwegian forum used to be OK, but it seems to have died. It was covered in spam the last few times I looked.)