To uninstall the software (plug-ins and app), please see the FAQ about uninstalling Toontrack software here.
On both macOS and Windows, you can uninstall sound libraries and MIDI via Product Manager if you have the installer on your computer still. To do that, click Show Details > Downloads and open the hamburger menu and you’ll find the Uninstall option there. Or use the Uninstall button in the Installation Info tab.
If you deleted the installer and you know what you’re doing, you can delete the sounds and MIDI manually. If you previously moved your sound libraries and MIDI, you know where they are and you can delete them in your file manager. Otherwise, you could download the installer again and then uninstall your expansion packs one by one in the Product Manager app as described above.
The sounds are stored by default in:
C:\Program Files (x86)\Common Files\Toontrack\
macOS (do not delete anything from any folder named Toontrack on macOS)
OS installation disk (Macintosh HD) > Library > Application Support
And the folders that contain sounds and MIDI are called EZDrummer (EZdrummer sound libraries and all your Toontrack drum MIDI), Superior Drummer (Superior sound libraries), EZbass (EZbass sound libraries and MIDI), EZkeys (EZkeys Instruments and MIDI).