Okay...think I've got it.
Only clarification I need now is in regards to how the "Contoured Sealing Ring" / turbo grommet is seated on the tube before you begin attempting to put the tube in place.

Right now, I've got the tube, and both o-rings are in their groove. I've already slid the grommet onto the tube such that it's sitting 'over' one of the o-rings. It appears that on the inside of the grommet, there's a groove where the o-ring should be seated once it's fitted correctly. That's where I have it now. Is this correct?

From this point, I should just be able (with the help of of a little oil) to slip the tube (grommet end first) into the "oil pan upper half" drain hole, right?