|In case you do not know how to do this (or an other reader of the forum reads this) here a small how-to:
First add the experimental repo to your apt /etc/apt/sources.list.d/debian.list
deb http://cdn.debian.net/debian/ experimental main contrib non-free
Then do an
After this do the following apt commands:
apt-get -t experimental install iceweasel
apt-get -t experimental install iceweasel-l10n-pt-br
And that's it.