(continuation from above)

That's more or less it. Oh yeah, decide to quit right now. Just as you're reading this. Never set a date for quitting, there are several reasons for this, but they aren't important. Decide to quit right now, visit your local pharmacy or some store that sell terrible tasting nail polish and some tools for prettifying your nails, and don't give up.

Just following these steps is no guarantee for success, not without determination and willpower. Also never forget why you want to get rid of the habit, it can be simple stuff like... not being ashamed of your hands when handing money to a cashier. Also, most importantly, don't give up halfway. Even if you don't think you need to, continue with the nail polish until it's been several months since you last munched on your fingers. And keep your pedicure equipment around for much longer than that.

Good luck!