Updated on Kisan Patel
In order to update the angular-cli package installed globally in your system, you need to run:
npm uninstall -g @angular-cli npm install -g @angular/cli@latest
Also, most likely you want to also update your local project version, because inside your project directory it will be selected with higher priority than the global one:
rm -r -f node_modules npm uninstall --save-dev @angular-cli npm install --save-dev @angular/cli@latest npm install
Source: https://github.com/angular/angular-cli/issues/4391#issuecomment-277199786