I used the iOpener and some plastic prying tools. Took me a solid 2 hours to get the back case off and the battery free from the midframe. No problems, and everything worked fine, but people should be aware that “15-20 mins” is wildly optimistic for your first attempt at this.

Glad to know about the importance of lining up the coil before removing it. Before prying the old battery and coil off the frame, I scratched a few registration lines into the midframe so I could tell when things were lined up properly during reassembly.

I found a video in German that shows this. I can't believe this iFixit guide fails to go into the crucial steps of the repair it's supposed to be about! Beware, this is not something a home hobbyist is going to be able to do. I got most of the way through my repair before I came across this german vid, and now I'm going to try to source a complete glass+LCD unit. Separating the LCD from the glass is hard enough, but you need special equipment to bond the old LCD to the new glass, and there's a good chance the two won't talk to each other anyway, based on the comments below.

https://www.youtube.com/watch?v=LvWPfUhp...

I used my toaster oven, set it to 200. I tried lower temps but wasn't able to separate the glass from the frame.

Difficult? Yes. Impossible? No. But putting it back together is the really tricky part. I found a German video that goes into it. You don't need to understand German to see what's involved here:

https://www.youtube.com/watch?v=LvWPfUhp...

Using a curved blade like the guide recommends, angle the blade straight down between the glass and the edge of the frame, mid-way along the bottom edge of the case. The metal of the case will flex *just a little bit*, allowing you to slowly rotate the blade so the cutting edge is now pointing towards the center of the watch instead of down towards your work surface. You may need to rock the blade back and forth, sort of massaging the curve into the seam between the glass and the metal before it works. And like they mention above, lots of heat. I used the heatpack they sell, put it in my toaster oven on 200. I started at 130, and went up in 20 degree increments until it worked.

Wish I had seen your comment before I ordered the glass. After digging around a while I found a much better guide on what's involved here. As you say, unless you've got a small pro setup OR have bought a glass/digitizer (is that the screen too?) combo unit, then this repair isn't really going to go well:

https://www.youtube.com/watch?v=LvWPfUhp...

I just installed a Samsung SSD, and the label doesn't go down. The Samsung logo faces down. Otherwise the holes in the drive holder don't line up.