Diaper changing is probably the task all new dads fear. How can we get men to realise there's really not much to it?

You can't. There's nothing you can say to us that would make us feel that "that's not much to it". It is a big deal. We know it's a big deal. We just have to do our job as expected of us whether we like it or not I still haven't gotten used to it. But I go through it dutifully like I do when I complete my national service. We don't have to enjoy it. We just have to do it.