Then you need to go through every component you've installed. Set the options to show you everything, and you will see a few options to choose from, "I" for install, "N" for no change, "U" for uninstall. You'll have to go through the entire list of options.
Comments
You will get two questions:
What should be done with all components that are NOT YET installed?
- Select "[S]kip them"
What should be done with all components that are ALREADY installed?
- Select "[U]ninstall them"
You can also run the following command from the command-line:
setup-bg2_tweaks --uninstall
There was no option to uninstall in the installer