Edit /etc/apt/sources.list, tambah baris berikut
deb http://mozilla.debian.net/ wheezy-backports iceweasel-release
Muaturun dan pasang pkg-mozilla-archive-keyring
wget http://mozilla.debian.net/pkg-mozilla-archive-keyring_1.1_all.deb
dpkg -i pkg-mozilla-archive-keyring_1.1_all.deb
Pasang Firefox/Iceweasel terbaharu
apt-get update
apt-get install -t wheezy-backports iceweasel