I did this battery replacement this morning. If you follow the excellent instructions and take your time this is not very difficult. One thing that wasn’t covered is that the replacement battery comes attached to a piece of plexiglass to aid in the positioning of the 5 pieces of the battery. The quality control on the positioning was not perfect on mine - I had to detach half and position, then place the other half. The placement of the replacement is not covered in the instructions - but isn’t very difficult.
I recommend getting the full kit - it was complete and made the replacement go easier. My new replacement is charging to 97% and has a capacity of 6358 mAh. This is almost 1000mAh more than my original battery was reporting! My old battery was only lasting an hour, this one is reporting 4+ hours.
Thanks! Great documentation and a solid kit.