###first, remove iceweasel
sudo apt-get remove iceweasel
###Open sources.list
sudo vim /etc/apt/sources.list
###Add this line
deb http://packages.linuxmint.com debian import
wget http://packages.linuxmint.com/pool/main/l/linuxmint-keyring/linuxmint-keyring_2009.04.29_all.deb
sudo dpkg -i linuxmint-keyring_2009.04.29_all.deb
sudo apt-get update
sudo apt-get install firefox
sudo apt-get install firefox-l10n-es
alt-f2
firefox