Changes

First , '''purging''' is done in two steps:<br />

:::<prompt>$ dpkg -l | grep -i oscar<br />

will display long lines starting with two letters, followed by the package-name and then the version and more stuff. <br />

The next step is to purge each package listed above, using:<br />

:::<prompt>$ sudo dpkg --apt purge <package-name><br />

Then '''installation'''If your long line started with three letters, especially if the third was an R, you will need to use the following:<br />

:::<prompt>:$ sudo dpkg -i -force-remove-reinstreq remove <deb filepackage name> Then, '''installation''': :::<br prompt>:$ sudo apt install ./<deb file>