Earlier quoted context omitted.
Apple: If the adhesive strip breaks, attempt to retrieve the rest of the strip with ESD-safe tweezers. If you can’t retrieve the rest of the strip, replace the top case Jesus. This is not what I'd consider "repairable". And that's not the only place in the manual where Apple just says "toss the whole top case out".
I replaced a screen on an iPhone 4 or 5 with a kit from iFixit. It was painful with the very basic tools provided and no magnifying glasses or understanding of what success was supposed to feel like. The parts aren't small, they are tiny, like 3mm screws, tiny bits of adhesive, things that are very fragile, etc. It took me like 3 hours. Experiences like that make me nope out of some DIY things.
It had 50+ absolutely tiny screws, requiring a 000 Phillips head, probably about the size of the little ones in iPhone 6s, but all about 2mm long.