But what about the iPhone 4S? Can you simply swap an iPhone 4 back onto a iPhone 4S?
Well, the short answer is "No".
Different Tab Configuration
Although the iPhone 4 and 4S appear identical side by side, they actually have a few differences that prevent one from simply interchanging the backs.
So if you happen to have a cool metal back for your iPhone 4, I'm afraid you can't just swap it out onto your iPhone 4S. Here's why...
Upon closer inspection, the back of the iPhone 4 and iPhone 4S have different tabs and spacings. So they will snap into the phone differently. We are looking at a GSM AT&T iPhone 4 back in this post, so perhaps a CDMA back swap is a possibility.
So now we know we can't just swap backs, how do we go about replacing the back glass on the iPhone 4S?
Shopping for a 4S Compatible Back
First thing is decide what new back you want for your iPhone 4S. There are a few options out there, but we resorted to our good friend, Mr. Michael eBay, for the cause. Be careful when purchasing here as it doesn't seem a lot of the sellers are up to snuff on the incompatibility between the iPhone 4 and iPhone 4S backs. Be sure to find a seller that can reassure you the back will work for the 4S. We put our trust and $19.99 in this seller
Replacing the Glass
When trying to remove the iPhone 4S back glass the first part is to unscrew the two bottom screws on bottom of phone.
Unlike the iPhone 4, the 4S screws require a mini Pentalobe bit (iPhone 4 required a mini Philips bit). Once those are removed, push the glass toward the top of the phone, sliding the glass away from the bottom.
After this, the back glass can be removed, and you can simply snap in your new glass. Trying the old iPhone 4 back on our iPhone 4S doesn't quite snap flush.
Put it All Back Together
Once you have your new back on, simply screw back in the bottom screws and you're done.
A cool new back for our iPhone to separate ourselves from the crowd.