1 
2 Why take apart from the back?
If the screen (glass digitizer) is totally cracked anyway and you can separate the front from the back, release the screws and take the digitizer off carefully removing the cable, why can't I do the same to replace it? It seems senseless to remove EVERYTHING from the back up (battery, logic board etc...) if it's possible to carefully get the flex cable thru the slot to reconnect the glass digitizer. Any anwers out there would be helpful!
Is this a good question?
Score
1
Because Steve Jobs has said it to be so.
Actually, under normal circumstances removal from the front isn't possible, or practical especially if the battery is what needs to be replaced.
by Chris Green