I've BTDT,GTTS. Keep up the praise (you're the best at burping/changing/pushing the pram...), ask for his advice, make sure Dada is the first word (lie if you have to), tell Daddy he is missed by baby... and then he's still disinterested until the baby is "interesting" - toddling alone, playing with balls and jabbering away.

Best of luck, I don't think you can push it because it didn't work with us. Seeing me nearly break with the strain and need wrist supports, that made DH do more and that got him happier to do more.