I had some trouble updating my Mac to macOS Big Sur 11.3.1. The update would remain stuck at “About 10 minutes remaining”, even after leaving it on all night.
The only way to get it to install correctly, was to reboot in Safe mode:
- Shutdown your mac
- Power it on again, and keep the Shift key pressed
- Release when you get to the login screen
That fixed it for me. More info on Safe mode here.