Help replacing iphone screen

Ok, so i dropped my iphone and cracked the screen. Bought an OEM new glass screen on ebay $40... Now I have to get the old glass out and the new glass in...

Q1: how do I safely get the old glass out without doing further damage? (i am guessing tweezers, or my fingernails)

Q2: how do I glue the new screen in? (i am guessing rubber cement... also I am guessing I don't have to remove the chrome casing and that I can just slide the new glass in)

Has anyone done this?? HELP!