apt-get remove iceweasel
sudo vim /etc/apt/sources.list file:
insert into
deb http://packages.linuxmint.com debian import
apt-get update
apt-get install firefox
apt-get remove iceweasel
sudo vim /etc/apt/sources.list file:
insert into
deb http://packages.linuxmint.com debian import
apt-get update
apt-get install firefox