I've got an Apple Standard Keyboard (model M0116) which is pretty dirty. It seems to me that the easiest way to get it fully clean would be to pull the keycaps off so I can really scrub them. I'm really worried about breaking something, is there a trick to pulling the caps off, or any gotchas I should I know before going into this? Or would I be best off leaving the caps on and just cleaning as well as I can with them in place? Thanks.