10 - 20 minutes
I had some oil that leaked out of my bowl and ended up in my ipod which ruined the screen and I did not want the expense of having to replace it.
The repair went well and the guide was instrumental. I did not notice that the new screen appeared to be damaged while putting it in and found it when I turned the device on.
Take your time and if frustrated take a step back.
iFixit Opening Tool
iPod Touch (3rd Gen) LCD
iPod Touch (3rd Gen) Front Panel Assembly