As previous reviewers have written; watch a video or two, work in good light, stay calm, be intentional (in other words stay calm and don't freak out), don't misplace the tiny screws

Instructions are so tiny that you can't read them without a magnifying glass but their are excellent videos online

Fortunately I had watched enough youtube videos of how to replace an iphone 6 battery that the insufficient instructions in the package didn't matter.