The whole process was pretty straightforward thanks to the instructions video. Only hiccup is I received the wrong part from iFixIt initially. Thankfully, after contacting their awesome support team, a new part was sent to me for me in 2 days and I was able to complete the repair !
Some steps look WAY easier in the video than they really are.
Removing the battery is really tricky, despite pulling the sticky tape tabs off as they do in the video, it seemed like the thing was just cemented in there. I was able to get it out by placing a spudger underneath and using it as a lever. But I had to use so much force that the plastic wrapping around the battery deformed a bit (thankfully the actual battery inside it was safe), and I heard the device crack at some point ; I was sure I had killed the screen or some other part... Thankfully after finishing the replacement process I was delighted to see that everything worked as usual ! So don't hesitate to really get in there with the battery.
Additionally, there's a little metal cover towards the bottom of the phone that must be removed at some point in the process. That was complicated too as the thing is clamped in there. My tip is to use a tool to deform the clamp parts of the cover and it'll just come off.
Also when putting back the side button flex (which is hard as !&&* to remove as well), make sure you get it right in there as the buttons will be loose and hard to press otherwise. Make sure you can press the buttons normally BEFORE you put back the rear cover !