The battery was not carrying a charge for any significant amount of time.
I, at first, watched several videos and read some articles. This helped me work out the steps for the repair. I am a technical biomedical engineer who work on multimillion dollar equipment so this was not that big an issue to deal with.
First of all, the tool kit I got with the battery is good. Not fantastic, but very good for it's purposes. Very important, there is not a prying metal tool in the kit. This was a big problem for the initial breakthrough of the seal. I had to make a pseudo wedge with a magnet strip for my car mount. Anyways, that was the end of the seal breaking process.
The next big issue was the battery glue strip. The plastic sandwich did not help with getting the glue out. It was actually very bad. The material stuck to the plastic it came in, stretched and warped easily and was completely unusable by the time I got it off the plastic. Now, I probably did something wrong here but did not see any instruction to remove the material properly.
And that is basically the end of the hard part. I am writing this experience on my phone so the replacement was successful. I am a happy customer for the most part so all good I guess.
In any case the DIY is excellent and well, it's not a fair comparison because I repair expensive medical equipment for a living. I do enjoy the DIY process thanks to these ifixit kits. I look forward to doing more of them.
One of the key takeaways you will always realize is that whether you are a professional or not, always, always have the right tools for the job. So ifixit ffs put a metal wedge in the kit.