Now I'm embaressed..I spelled school wrong in the topic!
hate to bring it up, but you also spelled embarrassed wrong. That is why I always try to spell check before sending.
And 'quitting' for that matter.
First, I would find out why they hate school so much. Is this an academic problem, or a social problem? If an academic roadblock exists, there are numerous resources that are available to remedy it. If it's a general lack of ambition and ability to follow through, I might suggest looking into some mental health resources. If the problem revolves around a social situation at school, I would attack that head on--sacrificing your education to a problem unrelated to coursework would be immensely foolish.
I would tell them in no uncertain terms that the lack of a high school diploma will absolutely be detrimental to their future in this. A person who drops out of school's earning potential is dramatically lower than someone with their HS degree (or equivalency degree). There is no way to sugarcoat the fact that if you drop out of school, you have drastically fewer opportunities in this life. Do a web search on earning potential for high school dropouts if you don't believe me. As a professional, if I had the choice between hiring a dropout and a high school grad for an entry level low-skill position that both could adequately perform, I would NOT hire the dropout. Their lack of ability to follow through with even the lowest level of educational achievement would be a signal to me that they were not someone I could count on. Harsh? Maybe. True? Absolutely.
Part of succeeding in this world is being able to deal with unpleasantness. We all have days we hate to go to work or school, but we do these things because the alternative is a life without achievement. (Reminds me of a great Drew Carey bit where he says: "You say you hate your job? There's a support group for that, it's called 'Everybody'. They meet at the bar.")
And to anyone tempted to post something detailing the successes of various high school drop outs should save their breath. These 'successes' are few and far between, and nothing more than a pipe dream.