20 - 30 minutos
The phone would spontaneously turn off between 45% and 65% battery, and would not turn back on until it had been plugged in for a few minutes.
I followed the step by step instructions on ifixit's website and the replacement went smoothly. It took about 25 minutes. I kept the tiny screws in a dish...they are really tiny.
The spludger was perfect for popping off the flat connectors within the phone.
You really will need a suction cup to lift the screen from the back of the phone. Luckily I could borrow one from my kid's little basketball hoop.