It was not difficult but a bit harder than I expected since I have to take off and reuse the original parts (Touch ID sensor, Front facing camera, ...). Have access to a heat gun in the lab helps. Overall it is pretty fun to do this myself.
One, make sure to follow the guide and note the screws, especially the tiny ones from the plate covers the connectors from the LCD to the logic board. They are actually different in length. Two, heat the adhesive that is holding down the touch ID sensor cable also.