Either way ... he ain’t running. Sorry, my bad here.
IMHO, the best method is firing squad in the public square. Doesn’t matter if it’s the electric chair or lethal injection as longs as he gets it ... long before the next 20 years of appeals drags on.
I don’t know the appeals process used in the UCMJ but like you hope it isn’t a long drawn out process. I think the President has to sign off on the actually execution when and if it happens, not sure of that though. Take care.