How do I get out of the army national guard?

okay, I enlisted in the army national guard back in november of 2008. I am on a dep right now. I'm about ready to graduate from high school. I'm scheduled to leave for basic in july. but, now I don't want to be in the national guard. how do I get out!? the main reason why I want to get out is because they refused to change my mos. I am a cav scout. I never wanted to be a cav scout, thats what my recruiter put me down for. I was kind of a whimp and didn't say anything right away about that not being the mos that I wanted. I just want out now. I want nothing to do with the national guard. my recruiter told me that I can't get out of the national guard. please! somebody! what do I do??