How can a solar system be destroyed?
A solar system consists of one or more planets orbiting a star, it can be destroyed by all of the planets being broken up, ejected, pulled away or consumed.
The destruction of a solar system requires destroying or removing all of the planets orbiting the star.
The "death" of a star doesn't necessarily mean the end of a solar system as the star remnant is usually still massive enough for planets to continue orbiting around.
If a planet gets too close to the star it can be broken up by gravitational tidal effects.
A planet can be ejected from a solar system if its orbit gets changed by proximity to the star, another planet, or another star into a hyperbolic orbit.
A passing star can also "steal" a planet by its gravitational pull.
Planets or even the star itself could be consumed by a black hole.