Commenting on an old post for the sake of future reference for anyone who finds themselves reading.
There's lots of people who can provide U2 IC replacement on the iphone 5C/5S/6/6+/6S/6S+ these days.
You can find someone close to you at http://boardrepair.info
It is definitely not something I would suggest someone who does not already do complex Micro BGA work to attempt. I see enough of them damaged from prior attempts, and it results in a higher cost that going straight to the experienced folk :)