your link is broken but the howstuffworks page is quoting from the Wikipedia, which sources the GPS guidance to an anonymous post on globalsecurity.org - itsself not a bad source - however the method of delivery is they open the back of the aircraft, push the bomb on a wooden pallet out the door, wait a few seconds, activate a parachute, wait a few seconds for the gps to kick in, whereby “fins” guide it to its location.

You’ll forgive me for being skeptical about 8m precision on a remote-controlled parachute from 35,000 feet at 400mph