Those "this is the first time I've ever done this" videos are being done by experienced techs. (Trust me - I've trained many.) Just melting the glue layer on the screen can damage ICs on the motherboard, rendering the phone useless. Pinching a wire means another parts replacement. (Pinching the antenna cable ruins it.) Forgetting to plug something in, or not plugging it in securely, means opening the phone up again, which risks cooking the new screen. There are more ways of destroying a phone than there are of fixing it. (Your choice, though. Save $100 or risk $180.)