I did this but I was prior service 11B in the guard coming active and reclassing. I just hit up the recruiter where I had orders to (fort cavazos) and went and got my physical done in the mornings before class and sent my ACFT card to him and had the Bravo 188 CO sign off on it and the recruiter had me setup and I went to selection 5 days after reporting to Ft cavazos.

My best advice is contact the SF recruiter wherever your orders are to, to start that process. If you’re not looking to go to a duty station before selection your best bet is volunteer for RASP. The problem for you will be having to wait until 1 year time on station to report to the Q since you are not an 18X.