@Rickkins
1) As for language:
EITHER
a) while in a book, tap the top part of the screen, go to the thrid tab, and tap the second from the bottom option. That is language selection. Find yours
OR
b) while in file manager, tap the top part of the screen, go to the first tab, and tap the second from the bottom option. That is language selection. Find yours
2) As for update, download the latest nightly build for kindle from
here, and then just extract both folders /koreader and /extensions to your Kindle's main folder when you connect it to PC. It should ask you to overwrite files, hit yes with confidence. Unplug Kindle from PC and start KOReader.
Yes, it is
that easy!