1) Tie a needle to some thread then cut the needle so that the only thing remaining is the threaded eye.
2) Drop it into the smaller hole near the front drop out.
3) finda way to stuff a small magnet into the hole at the crown and still be able to retrieve it. (Maybe stick a magnetized screwdriver into the hole)
4) Turn the fork upside-down, shake it around and pulll out the magnet and hopefully the needle head will be stick to it along with the thread.