$ sudo update-alternatives --config x-www-browser
There are 2 choices for the alternative x-www-browser (providing /usr/bin/x-www-browser).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/bin/chromium-browser 40 auto mode
1 /usr/bin/chromium-browser 40 manual mode
2 /usr/bin/firefox 40 manual mode
Press enter to keep the current choice[*], or type selection number: 2
