You don't need to drill holes, just use a long screwdriver and push those babies in, they are self tapping screws.

Here's a great investment for anybody building these planes.

Go to microfasteners.com and order a couple items. First is hex head servo screws 7/16" long, you will use them everywhere, not just in servos. They are so handy you'll want to buy a couple bags. Maybe get 1 bag of the longer 9/16" screws also.

Then order the long handled ball socket wrench, 5/64". You will feel like a god with all the things you can do and places you can reach. Totalo cost is about $10 for a wrench and a bag of screws.

TF