Hi! Welcome to PFK!! Hurray for you for wanting to transition your cats!
The thing is, you've got to get the dry food out of the house. As long as he knows it's there (and he can smell it) he's going to hold out for it.
I don't advocate trying to force a cat to eat by with holding food, of course, so there4 is that dilimma, of what to feed him, if you get all the dry food out.
Have you tried using incentives?
Things that have been successful are Forti Flora (a probiotic made by purina, but with animal digest as the first ingredient, most cats cannot resist it)
Vet's Best hairball relief,(My cats LOVE this stuff)
Freeze dried chicken breast such as
http://wholelifepet.com/whole_life_pet_products.php# (they have other proteins, too)
Have uyou been to this site?
www.catinfo.orgI have more to say, but out of time for now, just didn't want you to go unanswered, don't give up hope, IT CAN BE DONE!