That would require a special discharge from the active Army. We can't really help you on this end, you must pursue this from your own chain of command (and perhaps the IG). Be advised that if you're leaving the Army in a bad way, the Guard won't take you. Get out gracefully, even if that takes longer.
Normally, you will have to be within 6 months of your ETS date to transition into the Guard. The only way to attempt to process any sooner, is by submitting a "Request for Conditional Release" (DD form 368) through your unit chain of command.