Stuck!

I have a kitten stuck in my central heating duct, and by stuck I just mean it won't come out and when we stick our hand down there it hisses and not to be too sissy about it but honestly I'm a little scared of getting kitten claws stuck in my hand so I'm really not trying to be too pushy...anyways, does anyone have any ideas how to get it to come out on its own? Thanks, in advance...