I recently replaced the Lens Cover on my iPhone 4 without issue, here are the steps... follow at your own risk!
Things needed: Philips #00 screw driver or 5-Star screw driver, 1 x match, 1 x wooden chopstick.
Read all steps before performing as you need to do steps 4-6 quickly.
If you have a factory replacement lens cover, don't forget to remove the plastic wrap. Use a dull plastic knife and tweezers as to not scratch the new lens, it's lightly taped to the lens.
1. My phone consists of the Philips screws, so I used a <1mm flat head screw driver to gently remove the two screws on the bottom of the phone. Steady force, gently twist counter clockwise.
2. I pushed the back cover upwards, away from the charge port and the cover moved about 3mm allowing me to remove the cover.
3. The cover lens is glued in place and located on the iPhone cover you removed. Do not use knives or your fingernails as you will scratch the paint of your glass cover! Instead, hold the cover upside down with the inside facing downward. (Apple logo facing up). Hold the cover above your head. The next part is done quickly:
4. LIGHT 1 and only 1 match. Hold the flame directly under the Lens Cover allowing the flame to be 2CM away from the plastic. When the match is about 70% burnt, put it out.
5. Put the cover on a flat surface at the end of a table with the inside facing UP. (Apple logo facing DOWN)
6. Take the chopstick and press it against the lens from UNDERNEATH. At the same time, hold the cover firmly near the lens as not to snap your cover. Run the chopstick in small circles over the lens while pushing it UPWARDS (imagine poking a hole into the cover from beneath.).
7. Within 5 seconds, the lens and ring will POP-OUT toward you and no damage will be done to your cover. I suggest repeating with another match if the lens cover does not pop after 5 seconds.
8. Place your replacement lens cover into the hole (the existing melted glue will hold it in place) and reverse step 2 to get your back cover back on.
9. Twist your screws back into the bottom of the phone, turning clockwise. Don't over tighten in case you need to get back into the phone in the future.
Congrats, and keep a case on your phone to prevent the lens from getting scratched again!
email me your comments: [email protected]