Here’s a list of instructions that you can follow to stop your phone from downloading software updates automatically:

1. Open the Settings app on your device.
2. Tap ‘Network & internet’ or ‘Connections’ from the settings menu.
3. Tap ‘mobile data’ or ‘wireless connections’ from the settings menu.
4. Tap ‘advance’ or ‘software update’ from the settings menu.
5. Disable the ‘Auto-update’ switch.