How do you take seat belt buckles apart?

Went to my local Mopar wrecking (PLUG: Wildcat auto for all your Mopar needs) yard and got a complete set of black seatbelts out of a 68 GT. The Chrome is so so and fair for the age and the webbing is really nice, but, some of the Black textured buckles are starting to peal there coating. Does anyone one know how to dissasseble them? I'd like to clean them up and re paint them. Any good paint to reproduce the textured finish?

Thanks,

Dan