1 - 2 hours
I'm hard on phones and iPads. I can't even wear a watch. It ends up scratched, dented or in pieces within 6 months.
It's the second time for the iPad mini digitizer so it was much easier. First time for the phone and that was simple too.
The one recommendation I have is read the step by step instructions thouroughly at least once or twice before you do anything. It's good waay to prevent overlooking something or doing it out of sequence. I've avoided a few big self induced problems that way.
iPad mini 1/2 Front Glass/Digitizer Touch Panel Full Assembly
Metal Spudger Set
iPhone 6 LCD Screen and Digitizer