Mac OS X: Change display language
From IThelp
Change display language from norwegian to another language.
1. Click on the systemvalg icon.
2. Click on Språk og Region icon.
3. Under Foretrukne språk, Norsk bokmål should be above Englisk. Just mark English and dark it above Norsk. If you want another language as your display language, just click on the plus icon and choose yor language from there.
Your machine will require a restart for it to save your new settings.