My wife's IPhone 6 was suffering from Swollen Battery Syndrome. She quickly moved on to the next generation, so I decided to make an attempt to repair the old one, knowing that if I would fail, it would not cause a major upheaval, such as acute cellphone withdrawal.
The repair guide was very clear and accurate and very easy to follow, especially with the included pictures at every step. Since this was my first attempt to repair a delicate piece of electronics, I took it very slow and made sure I understood every step in the process, before moving forward. This made my repair time considerably longer than the average, but I was able to avoid issues like premature breaking of the adhesive tape.
I did fully remove the screen after I saw how thin and delicate the attached cables were, I could not imagine pulling and prying around the battery without causing damage to the cables and/or connectors.
During reassembly I struggled a little with reseating the connectors, because I was afraid to use too much pressure, but they eventually ended up securely in the right place.
All things considered, nothing but praise for the author of the guide, I would not have been able to pull it of without it !
I got confused when I looked at the pictures to apply the new adhesive strips to the new battery, until I realized that on the first of the three pictures the strips were shown upside down.
My advice to first timers of this kind of endeavor: take your time, it will be worth it, and with the help of iFixit, anyone can do it !