1 - 3 heures
I noticed some degradation in the sound from the earpiece then one day I could hardly hear anything and the earpiece became unusable. I use this phone for my business and needed to be able to speak to callers since this it the main number. I needed something fast and wasn't ready to replace the phone.
The repair went extremely well. I ordered the part and had it quick. I handed my phone and the replacement earpiece speaker to a young engineer who I had just hired a month earlier and who was the one who told me about ifixit. An hour later he handed my iPhone back to me in perfect working condition.
Be very organized. He spread a large piece of paper out on his desk and taped it down so it couldn't be bumped or moved. Then as he unscrewed each section he placed the screw on the paper, taped it down and labeled the step and description for the screw. He followed the online steps and used the recommended toolkit from your site. I might suggest a magnifier if you are an old guy like me trying to see the tiny screws...otherwise find a young guy who still has his eyesight. Everything went perfect.