1). I tried it in the assistant, but I cannot choose any language. The assistant shows me only the point 'autodetect' but no other language so I can only work with the default language which is english.
2.) Normally a second way is to choose the language in the preferences of openlp - but here I can also find only the point "auto detect".
I could find all language files In my linux folder /usr/share/openlp/i18n but it seems that openlp doesn't use this files or cannot read it.