Aaah, the most horrible micro-surgery electronics thing I have ever done!
According to the line above, this is not 'old man friendly', but a man's gotta do......
When you take the discards from the kids, there comes a time when the battery dies. The old phones made this easy, but all the new ones take the Steve Jobs attitude of 'Screw You!'. If you are an Apple-er, you just throw it out, but I save old junk, and run Linux on it. This Android phone is still supported by Mr. Google, and it is pretty good.
There are lots of utube videos on how to change the battery. They all leave one important thing out, sort of like the NSA versions of Internet bomb making. :) Basicially, you have to line up a T5 torx tip, and a fine Phillips. You will have an endless bitch of a time prying off the case, I ended up using a fine flat screwdriver tip, after breaking the daughters guitar pick. Then the stupid battery is all glued up, and a heat gun is useful.
I got it all working, and only time will tell if it is any better than the old one. I got the new one for 12 bucks from the Aliexpress site below. It takes a month to arrive.