There are a few ways. Number 1: Go to control panel, settings, network & internet, advanced options and enable set as metered connection. This should work for wi-fi.
If this doesn't work, right-click start, click control panel, system and security, click administrative tools, double-click services, scroll down to windows update, click it and then click stop the service in the top left. This should stop it from downloading any windows update and you will need to turn it back on before any update will be done. Hope this helps