In that case. You just need to fill the fafsa form, and get in contact with financial aid office at the college, and they will tell you what to do next.
But I can do this even when I don't live with them and they don't claim me in their tax forms?
Yes, it doesn't matters, because even with that, you are not considered as a independent student for purposes of applying for the federal student aid.
And what happen if they don't want to help pay for college or want to give me their information?