Interservice Transfer

[AceCrackshot]

I was just curious how possible it would be to interservice transfer from the USNR to the ARNG. I'm looking at potentially flying for a ARNG unit. I am current USNR enlisted, and I'm wondering if the process is possible, difficult, or if I'm stuck as a Naval Reservist for the rest of my contract. Who has to sign off on it?

Thanks for your help!