To update your Firefox browser on Linux Mint, follow the steps below -
1. Open the terminal by pressing CTRL + ALT + T or you can also search for the terminal from the menu of Linux Mint.
2. Type this command and press Enter -
"sudo apt-get update"
Typing the above command will update the package list of Linux Mint and ensure that you have the latest version of Firefox to install on your system.
3. Type the following command and press Enter -
"sudo apt-get install firefox"
This will install the latest version of Firefox and will replace any older version that you have previously installed on your computer.
4. Now, if you have the Firefox browser opened, close it and reopen it to use the latest and updated version.