Emergency Descents

Usually when I play FSX I set up an approach and am rarely in the upper atmosphere. So I can be careless with my switch placements.
The other night I was climbing in the 777 and hadn't switched on bleed air so at 20,000ft the plane started advising me I was drunk!

Being an adventurous drunk I decided instead of doing the sensible thing and turning on the bleeds I would zoom down to 10,000. However... You think I could accomplish a half reasonable rate of descent without tearing the wings off.  :-[

How should we accomplish this Lou?