35 - 40 minutes
I was replacing the LCD and, like many others, ended up cutting the power button cable.
It went very well! I ended up NOT taking the board out of the case because I didn't feel it necessary.
I would recommend not taking the board out of the case - it is a lot of extra work and it introduces a lot of things that could go wrong. It's tricky, but it's possible to do this repair by simply bending the PCB up to get to the volume buttons.