staging suizide is not what I'd call easy.
It always depends on the "type" of bully, but the best I came across was just getting something to make people laugh/mob them. Been mobbed myself for a few years in school thats exactly how I got out of it.
One guy could be brought near crying by joking about his "cheap" cellar-less house (sounds crazy, but status symbols and wealth was everything for him), and another drunkenly made out with a guy on camera. But I always had a strong backing from friends. If you cant find any in school search elsewhere, (sport, chess, warhammer, whatever you like ) clubs and so on. I know I'll be booed for this but I always found people from youth church groups pretty good to get along with.