Here's a helpful hack to get those screws out. It's not my idea, but I don't remember where I heard about it, so I can't credit the proper person.
I did this for my Nomad, so I know it works.
1) Find a pen that just fits down into the screw holes. You want the diameter of the pen to be just about the same as the head of the screw.
2) Take the pen apart, so all you have is the plastic tube (like a drinking straw).
3) With a match or lighter, heat up one end of your plastic tube. Don't get it too melty, but make sure it's soft.
4) Shove the soft end of your plastic tube into the screw hole and push it down onto the screw.
5) Wait a few seconds.
Now, when you remove the plastic tube, if everything went well, you should have a tool for removing these crazy screws. It worked great for me, but I had a non-standard pen that I did it with. Of course, it wouldn't have to be a pen at all. Find something about the right size and try it. Some pens have a little plastic tip that can be removed. Maybe that tip would be the right size.
Anyway, try it and post your results. It's better than drilling on your Nomad!