Please do not send me emails telling me this won't happen. I have no idea. This could be Roger Stone just floating the idea out there in an attempt to catch the ear of the President.
That said, I know for a fact that Roger and Judge Napolitano are very close, so it is possible that Roger has unique insight. And it would appear to be a smart move for Trump to make. It makes more sense then Roger's claim that Trump would nomniate Napolitano for the upcoimng Supreme Court vacancy.
So make of this what you will but at roughly the 4:30 mark, Stone says there are discussions about the Judge becoming Attorney General.