If someone is determined to learn Steely Dan BEFORE they have even learned to read music or learn the basics of chord theory, I'm afraid there's not much you can do about making it not daunting.
The thing is, if you take the time to learn the basics BEFORE you try that complex a music, you WILL be a good enough 'walk the walk' musician to play it. Or, you could take the Dnj approach, and simply sing over a commercial Steely Dan SMF... THEN it would be easy enough, wouldn't it?
No knowledge or chops needed at all.
So easy, a caveman could do it...
Here's a few Steely Dan song suggestions for Donny to 'walk' on:
Only a Fool Would Say That
Change of the Guard
The Fez (make a change from a chicken hat
)
Daddy Don't Live In That New York City No More and of course,
The Royal Scam
I'll bet he'd prefer "With a Gun', though
Well, 'Don't Take Me Alive'!
(We could play this one all day!
)