iPhone 3G Battery replacement.
Very tough repair. It took me 4.5 hours, not 45 minutes and I had to permanently cut a ground strap. Five additional tools needed. Broke the spudger tool sent with the new battery. No caution regarding battery disposal or regarding shorting the potent battery's terminals. Phone works though.
I nearly doubled the volume of text in the guide. I Still don't recommend this repair for several reasons, even after my additions and hints, but my iPhone does have new life.
1. Must cut a tiny, welded, golden ground strap from logic board to chassis. No mention of that in the instructions. Ground straps are not essential but do assist performance. My performance is probably degraded somehow. No way to reattach the strap. It just rests against the case now.
2. Mild adhesive holding the battery is Not "mild." It is very tough to remove. Of all my tools, only a triangular artist's palate knife was able to break enough of the bond to let me remove the battery.
Get a Triangular palate knife, not a standard one which is too wide. Costs more than the battery. A 0.002" automobile feeler gauge might do if trimmed to a long point.
3. A strong magnifying glass is essential. Best is to get one that fits over the head and allows you to use two hands. Sometimes 3-4 hands or a holding jig are nearly essential.
4. Reassembly: There is a micro ribbon cable to re-insert. You have to bend it just so, use plastic (not metal) tweezers and a toothpick to get it in place, while the two case pieces are aligned just so. All the while, magnification is required.
5. I recommended installing the SIM card as soon as possible, because otherwise, you might have to disassemble the phone to get everything correctly aligned, when you find out the SIM won't go in.
Other than that, it was a cool adventure. If it had failed, I'd have had the task of convincing my wife I needed an iPhone 4 because my 3G was forever toast. Ratz. It worked!