Change language completely?

Hi!

I was wondering, is it possible to change from english wordpress to swedish wordpress? I know how to change the .mo-files, but as far as I understand, that only changes the dashboard language, right? I want BOTH the dashboard AND the actual blog to change language from english to swedish. Like if I had downloaded the swedish version of wordpress in the beginning.

I also want wordpress to give me the choice to upgrade to the swedish language version whenever a new version of WordPress comes out (like it does when you download the swedish version and install it on a new site).

Thanks in advance.