Before you begin
Here is what happened to me: I wanted to install a new battery to my iPhone 14 but whilst removing the backcover the thing broke and had to be replaced so I bought a new glass backcover with most parts already pre-installed on eBay. Be aware: I am not a trained Apple technician, this was my first time doing this kind of repair. This is a complicated repair for some people and requires taking your time, don't be hasty!