Stereotypes exist because more often than not, they're based in fact not fiction. This is only sad because it is true. All too often, people are the source of their own stereotypes. To change the perception, one must first change the cultural zeitgeist. That can only be done at the source. As always, anyone can change but it's change for the better that's needed, my friend.
I am glad you said "more often than not" because sometimes the stereotype is imposed by the mind of the beholder. For example, I have no problem with Black folks, probably because I actively try not to judge folks by something as superficial as skin color. However, I live in a Lilly white neighborhood, when I see someone who is black walking up the street, for an instant I think, what are they doing here?
The media focuses on the negative regardless the subject. It is a rarer that they will cover a story about a successful or heroic black person, but the media appears to have no problem covering black gang shootings and such. Both events occur whether someone in black, white, brown, red or yellow. The media taints our perception of this causing us to develop some instinctual stereotypes as a means of feeling safer. It's a hoax of course, but we never-the-less fall for it.