StarTrekAngel makes a very good point.
Help him do the research he wants to do rather than pushing on him all the research you think he ought to be doing.
Don't come across as having it all figured out and inundating him with evidence.
If you attack the organization, he's likely to jump to its defense and you'll become the enemy.
Nudges in the right direction are fine as long as he sees you as helping him rather than taking over.
I should add that this isn't a matter of gender.
My advice to him would be the same if your situations were reversed.
It's a matter of not triggering the persecution mindset the WT instills in JWs.