Originally Posted by old rope
Leave the automatics in, let it overspeed, there will be considerably less paperwork.
yeah, sure - do what you can to prevent/avoid the situation but has an aircraft ever crashed from a minor speed excursion in the cruise? no need to rush into things.
general comment.
also, in climb the engines are targeting N1 - engaging a speed mode through 'alt' or whatever can reduce the thrust without mixing things up (as ned says above), add speedbrake if needed.