Have you gotten any further? I was doing a battery replacement and while removing the screen it cracked. Since I didn’t have a spare screen, I reassembled the phone with the cracked screen and saw some flashes of light but was dark. Upon attaching a replacement screen I get nothing on screen but can feel the vibration of the phone restarting. Tried a second replacement screen but no different.
Did you ever resolve this issue? I’ve just done my battery / screen replacement and have the same thing. I can feel the phone restart from the vibration but the screen never lights up.
The guide could definitely use more details about the proximity housing as well as the camera ring. I used a magnifying glass to pick at the corners and they each popped off. To keep them in place I used a very small piece of double sided tape. I figure they would stay in place once it's all reassembled.
As for completely pulling the camera off the LCD shield like in the picture, if you're going to transfer the shield to a new LCD screen I don't think it is necessary to remove.