There are some methods to install program in Ubuntu. The easiest way is using Ubuntu Software Center or Synaptic. Another way is using terminal. You can use dpkg, apt-get, or aptitude.
dpkg is used if you have .deb file. To install package use this command.
$ sudo dpkg -i package_name.deb
To uninstall package use this command.
$ sudo dpkg -r package_name
Another simpler method then dpkg is using apt-get or aptitude. You just need to connect with package repository server through internet or LAN. Then you can install package use this command.
$ sudo apt-get install package_name
To uninstall or remove a package use this command.
$ sudo apt-get remove package_name
But above command will leave data and configuration file of the package. To remove data and configuration file use this command.
$ sudo apt-get purge package_name
By using above command will remove data and configuration file but not for dependencies which was installed when main package was being installed. To remove unnecessary dependencies you can use this command.
$ sudo apt-get autoremove
Before you can install a package using apt-get you should configure package repository location. See this post to know how to configure package repository location.