Where can I get more information about the process of transitioning to AD and reclassifying to 15N?

So, you've submitted the 368. Obviously you've made contact with a Recruiter to get this ball rolling. That's step one.

The rest of the process is going to be (initially) a wait game to see if your CoC will approve your release. More often than not, CoC will sign off approving. However, there are rare times when it is denied. But, I digress. Once the 368 comes back approved, then the real work begins. Which mainly consists of ensuring you pass all the usual crap at MEPS (yes, you will go thru that process all over again). I think you'll have to do the ASVAB again. At least, I remember having to redo it when I was going from Reserves to Active......many many moons ago. Since you'll be under Prior Service rules, you will be processed (pretty much) last by the MEPS Career Counselors. By the time it is your turn to select jobs and review contract, almost all of the Initial Enlistee hopefuls will be done and gone. If, by the time it's your turn, 15N is still available and you meet the pre-reqs, then it's yours. But, I want to warn you, BPT have another MOS (or 3) as a back up.....just in case.

Once all of that is done, you've got a job picked, signed a contract, cleared MEPS and did the Oath (again), you sit back and wait for orders to ship. Easy peasy.

But as for your original question, your Recruiter and Reserve Career Counselor should be able to provide guidance to your RFIs.

I'm sure someone may know. I was in the army reserve but here is at least one AGR.

There's always E7s who know the particulars and may be able to answer some of your questions. They will probably answer you in the next 48 hours. I just retired but I never went active duty except permissions in the guard or in the reserve so My knowledge is limited to only what I experienced on deployments, schools or on short tours.
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MAJ (Join to see) 1SG (Join to see) CSM Charles Hayden