What you need to do is get a 4187, and a 368, both are DA, forms if I remeber right the 368 might be a DD form I cant remeber off the top of my head.
Im and RA Army recruiter.
So, the easiest way to do this is to contact your Army Recruiting station. Be ready to go to active duty Army, dont waste someones time if you dont have your heart, and mind set on it.
By the way you dont have any law voilations since you have entereded the NG? Excluding minor traffic tickets?
This can keep you from being eligible to enlist in the Army, just talke to a RA recruiter.