You can uninstall an installed software from your Ubuntu system from command line as sudo. But at first look into the installed package list.
$ dpkg --list
From the list you may copy the package name.
Use apt-get remove command:
The apt-get remove command will remove a software from your system but it will keep the configuration files and any plugin and settings that you might have installed later. This helps in keeping the same settings when you want to reinstall the software.
Run the following command as sudo
$ sudo apt-get remove package-name-here
The system will promt with a y/n option for re-confirming the procedure. If you press y the process will remove the program from your system.
Use apt-get purge command:
In order to remove an application from your system completely you need to uninstall the package using apt-get purge command. As the name suggests, this will purge all the associated files and settings.
And later if you reinstall the software, it will be installed with completely new settings.
Run following command as sudo
$ sudo apt-get purge Package-name-here
Again you will be asked to confirm with y/n option.