when i was working on my squier jazz bass body, i had to fill in the control plate holes and redrill them because they were stripped...
i would imagine that all you have to do is just put in wood filler.
take some plastic wood and just push it down with your finger a million times, and push it in with a toothpick every so often.
once you have as much as you can get in the hole, let it dry and then redrill it.
you need to tape all around the hole, otherwise your going to have crap all over your finish...
i taped around the holes with 6 strips of electrical tape in a hexagon type arrangement.