Did you drop the phone? Is the screen cracked? Is there a specific reason for wanting to open it? Unless you have a microscope and are a pro,or have replacement parts lying around,opening it probably won’t do much good for you. If the screen is cracked,it needs to be replaced. If not,a drop could still have damaged it or the board. Please give a bit of history. I’ll try to help.
please don’t try to take the back off again. It may break. I’ll look into it for you. Reply back if you want me to help out.