Using following commands to uninstall :

npm uninstall -g @angular/cli
npm cache clean --force

To verify: ng --version /* You will get the error message, then u have uninstalled */

Using following commands to re-install :

npm install -g @angular/cli

Notes : - Using --force for clean all the caches - On Windows run this using administrator - On Mac use sudo ($ sudo <command>)

  • If you are using npm>5 you may need to use cache verify instead. ($ npm cache verify)