You can't just buy the glass I got on for my wife's 4 And you can't separate the glass from the digitizer without ruining the digitizer so if you do it yourself just get a glass with digitizer for 40 bucks on eBay and replace it. Not hard just a little time consuming being careful with the small parts
my Razr Max fell from 18ft in the air, landed face down on a concrete floor...... didnt even scratch the glass. has been dropped from a few feet dozens of times. has no screen protector, just a small plastic case that slides into a holster. gets covered in dirt/dust daily, wet, beat up and it still looks brand new after 5 months. im not easy on phones at all, but this is by far better than every other one ive owned. i know this doesnt fix your screen, but if you can make the switch.... you wont be asking about broken glass anymore or doing surgery at home.