Well, if your young and have no kids or anything, go for it. I did 18 hour days for 2 years and got nothing but another bill. Too old with too many repsonsibilites to take the cut in income starting out a new career.
Don't believe the "you'll be a BMW tech when you graduate and making 80K a year" garbage. Just a forewarning there. I graduated top of my class, passed in my first round of ASE certification exams and still would have to start by busting tires down and oil changes.
But like I said, your young enough to it, so good luck, it should pan out for ya.