You can remove Plesk as any other program in Windows: go to Control Panel > Uninstall a Program, select Plesk and click Uninstall. For the complete instruction on how to remove programs in Microsoft Windows, read this article:

You can also remove a particular Plesk component from the Plesk user interface, at Tools & Settings > Updates and Upgrades > Add/Remove Components. For details, refer to Adding and Removing Plesk Components.