Hey, I finally got around to put the S7 Edge battery in my S6 and have made a blog post detailing the process step by step and with a lot of pictures. Hope its of some use to you.
looks different that original, anyway I don't suggest this type of replacement, even if is same voltage charging ic from s6 is design to charge a smaller capacity battery than s7
Battery percentage ...
That's not quite "almost" the same size, the giant bulge created by the excess battery width is actually quite dangerous. All those exploding phones you see in the news, that's what happens when your battery is too big for the compartment it's in...
You can check out my attempt to do so. It is not that hard, although I scratched tha paint from the inside when removing the back - its only cosmetic and not really noticable. If you have the proper tools its not such a big deal - the S7 Edge batt...
Short noob-friendly tutorial on how to flash:
List to download:
2. Stock kernel with TWRP 188.8.131.52
3. TWRP 184.108.40.206 - latest working TWRP for Xperia S
4. nASOP ROM - see xda thread
5. SuperSU v2.37
6. Google Apps for lollipop