I successfully changed my battery w/$35 kit. The Sony battery from iFixit works perfectly. I started with the corner next to the jack. I left the screen cables on, used forehead to keep phone open when prying out old battery. Hairdryer twice to warm the glue. The shorter screw for battery cable cover is too hard to replace first. A short, inexpensive Phillips 00 from iFixit worked better than my Pro Phillips - it had the right magnetism to hold the screw head on the tip, and fit inside the phone for aiming the screw into hole. After replacing the longer screw, the short one was much easier to insert with the cover attached. I slotted the top end of the phone screen in first, and the whole screen snapped into place on the first try. I have the nerve to do this repair again. Tip: Use iBackupBot to check batteries before and after. The old one had 598 cycles, had dropped to 1000 capacity. The new Sony battery shows 1500 cap. vs 1430 design. Extra 5%! I bought it in Dec 14, and it was made just 2 months earlier.