10 - 30 minuten
The factory battery started dying with almost 20% power left. We decided to replace with a new one since batteries get worn over the years.
I read through the guide at least 3-4 times before I was comfortable tackling the repair. Even though people say it takes "10 minutes", that's probably for someone who has done something like this before or for someone who's less cautious. I took about 20-30 minutes.
In the end I followed all the advice of the article, and some tips from the comments.
I recommend wearing some type of latex glove to prevent transferring fingerprints to the parts. The battery connector is definitely the trickiest as it moves around immediately after you take out the screw holding it in.
I found popping the battery cover out was a little tricky since it's secured quite well. And inserting the new connector took a little time because it's difficult to align things and have them insert properly. Taking out the old battery was ok, just be aware there's adhesive backing all around so you need to pull with some force to remove it.
When I turned the power on after I was done, I had the "searching" issue others have seen. I connected to my computer where I had just done a backup before the procedure, and my carrier was found.
After that it was smooth sailing. Thank you iFixit!!