20 - 30 minuten
We were only getting about 30 minutes battery life. Rather than junking the phone we decided to give it a second life
Dismantling was not a problem. I followed the photos.
Assembly was a pain. The screwdriver included in the kit was only lightly magnetic and the screw would drop off. This meant shaking the phone to get it out of hidden places. I was confused by the screw sizes - My phone had different lengths in some places.
The real problems came with reconnecting the two antenna connectors with the round plugs - They would not align and one is still not connected - I may have damaged it.
At one time I thought I had that round plug in place and started to attach the display leads, The first one has to slide into a slot and I assumed that it had to go in fully. I took it to the Apple store and they told me it only goes in a short way. That was when I found that one of the connectors was under the circuit board and I had to restart.
The photos are fine for dismantling but do not help fully with assembly. I found a YouTube that showed the assembly in detail. He showed how to insert the circuit board taking care to leave the connectors clear, he showed the assembly of the slip in cable clearly and he explained how to align the antenna connectors. The iFixit video is very superficial and does not help much.