So, there are hundreds of species of bristle worm. And maybe two or three of them can cause problems in an aquarium. But they are very rarely found in aquariums.
The ones you see in home tanks are generally harmless scavengers that only get 1-2.5 inches long and simply clean up after your fish. They multiply and get bigger if you overfeed.
As for getting rid of them... Why? Not hurting anything, interesting to watch. If you REALLY want them out, don't use your fingers. Tweezers or forceps. Those bristles can hurt like tiny splinters. Coral Banded shrimp will eat them (along with anything else it can get hold of).
They won't hurt a healthy fish or coral.