Just wanted to add this: I think the comment below is probably correct in terms of being safe and not messing up your phone but another user pointed me towards this possible solution: https://www.youtube.com/watch?v=oUJ4Fv0f... The iPhone 7 lens housing IS interchangeable with the 8
You can buy individual keys online, yes... just google it. People mark it up because they know about folks like you that need single units. They're easy to put back on. When I messed up a few of mine, Apple just replaced the whole top case, saying they don't do single key replacements.