To install a .deb file, simply double click on it, and then select Install Package

Alternatively, we can also install a .deb file by opening a terminal and typing:

sudo dpkg -i package_file.deb

To uninstall a .deb file, deselect it in your package manager, or type:

sudo dpkg -r package_name

(For more help see: Ubuntu Desktop Guide – Install/uninstall .deb files.)