Foxniner,
Listen to your aircraft manufacturer they know better than all of us and have genuinely produced a procedure to follow which covers all situations for all types, truely incredible.
What will happen at FL400 is that you will decelerate and begin a descent. During which you then complete the rest of the QRH and eventually get to setting pitch and thrust from the PI section.
Lord spandex, if you have a Boeing FCTM it should have been updated at the same time and is in there.