is it possible to change the english to the portuguese?

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hi, linuxers,
I've downloaded the knoppix 5.1 and I'd like to install it in my hd. is it possible to change the english idiom to the brazilian portuguese one?I've read in a linux handbook if the distro has the kde it's possible to shift the idiom by downloading via terminal by typing "sudo apt-get install kde-i18n-ptbr". how do I make it? do I have to configure something else? i'd appreciate your helpful hints and suggestions. Best Regards.

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