Removing installed packages can be done via one of the two tools: apt-get or dpkg.
Every command has to be run with super user privileges sudo.
1. To remove an already installed package (packages), run:
sudo apt-get remove package1 package2
2. To remove a package with its configuration:
sudo apt-get purge package1
3. To remove not needed dependencies, after removing a package:
sudo apt-get autoremove
4. A package can be removed from the system via dpkg tool as well:
sudo dpkg -r package1.deb