By far the worst part is the battery cover is welded to the back of the case with gluonium which cannot be removed with anythhng but gamma rays and kryptonite, so as the guide says,, long thin knife is what you need. The battery is glued in the same but you don’t care so much at this point :-) See step 3, the tabs top and bottom, you remove the cover by flexing it away from the frame at about the mid point.

Time and patience, gently, gently teasy monkey…

Ok, this may not be quite as easy as it looks. On my phone it was *well* glued on the bottom two corners, enough to defeat a plastic spudger, so start on the long edges towards the top.

Next, the battery connector will likely be straight on the new battery, so bend it into the approximately right position before you insert the battery.

Apart from that, all comments above worth reading. My wireless charging wasn't working, but I gave it the magic massage around the 'S' and it's fine now.

Total time ~15 minutes, most of which getting it open.