You us missile effector(s) against individual satellites. Hence why clouds of smaller satellites are more survivable.

If kinetic, then a bunch of space debris are created. Some larger pieces, some smaller. If those intersect with other satellites, they may generate additional debris (see Kessler Syndrome, what parent was talking about).

But on the other hand, low earth orbits (where Starlink et al operate) will decay much faster than higher orbits, so it's a {wait time} problem rather than a {have to cleanup manually} problem.

And also space, even Earth orbits, is big. Satellites manage not to hit each other most of the time. A limited strike (e.g. the previous US or Chinese demonstrations) probably won't cascade.