Well it all depends. If you have a true inclinomoeter you can do it all in one shot w/o dropping the DS. I use a basic angle finder, and do the steps above to get the yoke and tranny output angles. You do need the DS angle to get a complete setup though so if it was accurate don’t scrap your reading.
If you don’t have a flat plate to get the reading off the yoke, a deepwell socket the size of the joint beaing caps works as well. Lock into the yoke with one of the bands and put the angle finder upt o that to get your reading. you should use that if the yoke is severely corroded/rusted