45 minutes - 2 hours
Power button did not function, battery had a dead cell, and the camera had a particle of dust inside the camera that left a spot on every picture.
It was my first time taking apart an iPhone 5 so I took my time and went slow, following the guides precisely. I had a sheet of paper to keep all the screws and parts organized. I could not have done the job without the Pro Tech Toolkit! It took me about 3 hours to replace all three items.
Take your time. Some things take awhile to figure out, just don't rush it. Now that I know how everything comes apart I think I could do the same job in about an hour. If anyone needs help or has specific questions I'd be happy to help!