How to install newest Firefox on Ubuntu 13.04, 12.10, 12.04 on Linux Mint 15, 14, 13?

In this article I will show you how to upgrade your Firefox to the newest possible version on Ubuntu and Linux Mint.

Close Firefox and open terminal and add new repository:

sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa

Update everything:

sudo apt-get update

Finally install Firefox. Changes will take effect without restarting OS.

sudo apt-get install firefox