To change the language - push 10 & 1000 together -enter 19 and push the set/reset button. You'll see "Lock on" Enter the number that is the sum of the current day and month (today, Sept 2nd it would be 11 - the sum of 9 & 2.) This unlocks the OBC - now enter 11 and push set/reset. You'll see an indication in the OBC window of the current language. To cycle through the language options cycle the 1000 button. When you have the one you want push the set/reset button. To relock the OBC enter 19 - set/reset - you'll see Lock Off and push set/reset again. The OBC is now relocked.