Cut a neat square out of the cieling slightly bigger than the hole. In fact, it is a standard practice to install drywall around light fixtures to. Web there are two can lights in ceiling here, with cree retrofit led bulbs, and both are missing chunks of drywall like the light fixture in photo.
Diy painting light fixtures
Diy plumbing pipe light fixture
Ceiling diy light fixtures
Drywall How to patch this ceiling hole the new light fixture does not
Web the right way to do this:
Web if you can't sand it out perfect with the 20 minute, for a small repair like that use spackle (all purpose drywall compound is better, if you have any around) on top of.
