how to install and keep uptodate the latest version of firefox on debian?

First install:

• open a terminal
• wget -O FirefoxSetup.tar.bz2 "https://download.mozilla.org/?product=firefox-latest&os=linux64&lang=en-US"
• sudo mkdir /opt/firefox
• sudo tar xjf FirefoxSetup.tar.bz2 -C /opt/firefox/
• sudo mv /usr/lib/firefox-esr/firefox-esr /usr/lib/firefox-esr/firefox-esr_orig
• sudo ln -s /opt/firefox/firefox/firefox /usr/lib/firefox-esr/firefox-esr

Getting the last update:

• open a terminal
• wget -O FirefoxSetup.tar.bz2 "https://download.mozilla.org/?product=firefox-latest&os=linux64&lang=en-US"
• sudo tar xjf FirefoxSetup.tar.bz2 -C /opt/firefox/
• restart firefox