To uninstall Kentico CMS from your computer, open Start -> Control Panel -> Programs and Features. Right-click Kentico CMS and choose Uninstall from the context menu.
The uninstaller will delete all files created on your computer except the deployed instances of Kentico CMS - it means that the database instances and the website folders will not be removed and you have to delete them manually if needed.
Page url: http://devnet.kentico.com/docs/5_5r2/devguide/index.html?uninstallation.htm