Instructions to Replace Your iPhone Back 

OK, so you have a broken back glass and you want to replace with a new one.
Locate the 2 screws on the bottom of your iPhone.
Take the Pentalobe screw driver that we have provided to you and unscrew the 2 screws found on the bottom of your iPhone. Be sure you keep these in a safe place as they will want to disappear if you don't keep track of them.
Take your iPhone and flip it so the back is facing up and grab your iPhone as shown. Use both of your thumbs to press and slide the back upwards.
Once you have pushed the back up far enough you should be able to seperate the back from the iPhone frame.
Now line up the tabs on your new back to the holes on your iPhone frame. Slip the back in to place and now using your index fingers as shown you should be able to push your new iPhone back in to place. You may not be able to totally push the glass all the way down so don't worry you will be able to do so when you re-install the 2 screws.
Now take the 2 screws you removed and put them back in. Use the Pentalobe screw driver to screw them down tight. Do Not "Crank" on these screws as you will strip them out if you try to tighten them to much. Just make sure they are snug and you shouldn't have any problems.
That's it! Enjoy your new Back!