Changing oil

The bulk of your oil volume is in the tank. It will drain completely up-right or on side stand. The sump only has something like a quart and a half in it. (provided the bike has not been sitting un-started). Since most Gen 1 Rockets have 2 sump drain holes most of the sump oil should come out on the side stand. There will always be a little of the old oil left in the engine. Don't sweat it. No need to be OCD here guys.
 
If they are OCD leave the plugs out flush it with some new oil let it drain ,plugs in fill it up,use a bunch of oil lots of oilfield hands are now unemployed
 
Good idea Breeze. A full flush should get all the nooks and crannies cleaned out. Would you suggest maybe a 5 gallon bucket of motor oil flushed through the engine would help both the engine and the oilfield workers ?