There are a few inaccuracies on this guide. As with any unofficial guide, use your common sense.
First, on the bottom cover, the 2 screws closest to the rear and center are DIFFERENT from the other 8 (10 total on the bottom). The author of this guide said they're all the same which isn't quite true. Use the Pentalobe screwdriver for these screws and make sure you find the 2 that are DIFFERENT or the bottom cover won't close just right.
Second, the screws for the heat sink should only be accessed by a T5 torx, not the pentalobe. This was omitted from the required tools list.
Third, there is no battery sticker.
Fourth, check and re-check what you see vs an online guide, especially since nothing from iFixit is official Apple documentation.