I had this issue too :( The screw head is almost exactly the same size as the hole for the dvi which makes it very stubborn to get out! The only way I was able to get it out is by removing the top case (keyboard and trackpad) and then using two small thin needles. One needle to slip in between the case and the dvi receptacle while using the other needle to manipulate the head of the screw. After about 5 minutes of finagling I was able to get it out! I hope this never happens to anyone else but thought I would post my experience in case anyone else finds it useful.