Losing the metal clips that you're talking of (marked in green on the bottom photos) is the top reason for abnormal Wi-Fi operation after reassembly. Here are two images, which I shot, that better depict the cause of the issue. Once you lose that piece, you have no option but to order a replacement cover. In case the images don't work here, here's an external link.
Losing the metal clips marked in green is top reason for abnormal Wi-Fi operation after reassembly. Here are two images, which I shot, that better depict the cause of the issue. Once you lose that piece, you have no option but to order a replacement cover. In case they don't work here, here's an external link. I've also lost my 1.4mm "hole" (or nut as I would call it). I still have it but I don't think there's a way to fix that back onto the logic board. Anyway, I keep a loose dummy screw there to make the needed contact and so far I've had no issues. As regards the EMI fingers on the antenna cable hat runs by the loudspeaker enclosure, they are really overrated. I had them all snapped off and there were no issues with Wi-Fi, 3G or 2G signal. Then I replaced them just to be sure - same thing, no difference.
Losing the metal clips marked in green is top reason for abnormal Wi-Fi operation after reassembly. Here are two images, which I shot, that better depict the cause of the issue. Once you lose that piece, you have no option but to order a replacement cover. In case they don't here, here's an external link.
Another solution that I've seen being sold (again, haven't tried it) is a set of special drill bits. The drill bit ends with a reamer on one end and a screw remover on the other. And I quote: "The reamer bit drills out a small conical hole in the damaged screw head, while the screw removing bit digs into the sides of that hole and pulls the screw out." It's something like this piece from Amazon (Alden-8440P-Grabit-Damaged-Extractor) though there are many alternatives: www.amazon.com
I've seen a special liquid product for stripped screws at the hardware store. I've never tried it myself but you apply it on the stripped head and after it cures a bit, it's supposed to help you unscrew the thing. Here's the product that I'm talking about ww.bison.net If the link doesn't work for you, google it, it's called Bison Grip or Bison Screw Grip.