before I do something stupid

I've managed to get myself a full set (4) of genuine mud flaps, now do I take it that these get screwed in using the existing screws that hold in the inner wing? Or do I need to redrill??
Also, I want to paint my front/rear VW badges black. I can see how the front 1 comes off, but how do I get the rear off, and how do I reattach it afterwards?
If anyone has a spare front frill VW badge going, please let me know

Thanks
Toby