how to manually uninstall node , npm and angular cli completely globally n locally

On my Windows 7 machine, I'm unable to update/uninstall an existing global angular-cli instance following the approach outlined https://github.com/angular/angular-cli

using these following commands npm uninstall -g @angular/cli npm cache clean npm install -g @angular/cli@latest

i tried to uninstall angular cli then nodejs and afterwards installed latest nodejs and angular cli. then after when i run ng -v i get errors. so i want to completely uninstall node , npm and angular cli globally and locally completely so that i can install fresh copy.

via angular user