Here's what you do, you'll need a friend for this.
Sit on an armchair and have your friend tie your hands and legs very tightly to the chair so you wont thrash around too much. Now have your friend grab a wrench, preferably one of those wrenches that you can adjust for a better grip.
Have him slowly rip your nails until they're vertical with your fingers, now this part may be a little painful, but eventually it will subside.
Now with a hammer, have him hit each nail until they're buried into your fingers, it may take a pick, and some may pierce into the wood, but I assure you, you'll never bite your nails again.
