My Sony Xperia Z3 screen is broken

My Sony Xperia Z3 screen is not working anymore after used it underwater. It is pitch black and the water damage indicator is pink from white, it means that the phone is broken because of water damage but the phone is still working, whenever message me or pm me from fb messenger, the phone is responding. Also when I press the shutter button, it will vibrate and you will hear the sound of the camera app.

How can I access the files on my pc or how can I reformat the phone, the screen lock is on and I can't unlock it?