Got a battle buddy that is indef but now wants out. Is there any way he can request to be released from service?

The only thing that keeps you tethered to remaining in service in this situation is operational needs of the Army. The commander could say no.
He could request discharge, transfer to a Reserve Component, IRR, or retire (if eligible).
Were I to advise this Soldier, I would ask some questions about why and assuming that it is something along the lines of having enough of the life, wanting to start a family/ career, etc, suggest he try out the Reserve or Guard so all of that time in isn't lost. Getting back in once you are all of the way out is much more difficult than adjusting your component and commitments as life events occur.

I'd advise him or her to see his or her Company's retention NCO. I found some info that says that an NCO can be voluntarily released from service similar to an officer just so long as they met their reenlistment obligations but I'm not sure how up to date it is. Source as follows:
http://www.eur.army.mil/news/archives/2007/releases/2007-07-004_IndefiniteReenlistment.pdf

He may be able to submit a request for transfer to the IRR or Reserve if he is on Active Duty.