The basic tool is Java based and requires Java 6.0 or later to be installed.
When upgrading simply install the latest release over the your existing installation. There is no need to uninstall your current version first. All of your settings and results should be preserved.
Windows: Just double-click the downloaded file to install. See the ReadMe.txt file for uninstalling.
OS X: Open the .dmg file and see the HowToInstall.txt file for instructions on installing/uninstalling.
Linux: Uncompress the downloaded file using: 'tar xvfz totalvalidatorbasic.tar.gz' then read the instructions in the ReadMe.txt file for installing/uninstalling.