To answer your question, the simple answer is yes you can separate the lcd from the glass.
Let me explain: The lcd and glass are fused by an adhesive called loca. It cannot be heated up with a heat gun. In order to make the adhesive workable, you will need to get a special machine called a lcd separator machine that has a sort of hot plate used to heat the screen so you can take it apart. I used a tutorial on lcdseparatormachines.com to take my screen apart. The machine proves itself very profitable as the glass replacement is one third of the price then the hole assembly so you can make a lot of money doing the repairs.